The Road to Organics
Several friends well they were friends asked me if it were possible to place everything found separately in the book on Organics in the one section. Well here it is. Trust me a lot of what you read here is either found in other sections, rehashed along with new sections on how to get certified or just being totally organic at home.
Organics is not farming conventionally and substituting organic inputs, in place of chemical fertilizers, herbicides and insecticides. It is an overall transition to total sustainability on the property and farming with nature. A percentage of the property must be left as natural stands or revegetated to its originality.
I will broaden the subject but everything written here is what we personally experienced or are the experience of close friends; including the memory of my very best friend and mentor David Callaghan of Korora, told me. In fact while we both had a life time of experience in organic growing neither of us had the in depth experiences in controlling Arthropods, Gastropods or other problems foisted upon those who chose to ignore organics and insisted in growing with toxic chemicals. So while we may not be the best persons to discuss this topic, what we can discuss is the experiences of how we avoided those experiences foisted upon others through complete integration with nature.
Our observations and discussions were about “what if” and “What shall” we do if this bug or problem besieged our properties. The beauty of organics in our experiences were that experiences rarely came our way and solutions were found prior to the experiences evolving. We often reflected together how; “In nature, one imbalance creates a counterbalance which attempts to restore the balance in a never ending flux of ebbs and flows.” andi Mellis.
Here for example, where land is left bare grasses and other annuals begin to grow followed by perennial herbaceous shrubs then woody shrubs and finally the giants of the landscapes the trees. There is an order that must be followed where the fluxes play an important role. Man interrupts that balance/counterbalance then claims the counterbalances to be weeds instead of a logical order of development within the landscape to restore natural productivity and recycling.
Agriculture is no different to nature, so as long as we managed to find the natural way, that nature intended to use to restore the balance, then the balance can be restored without the need for much intervention and without creating further problems that would need more intervention. The aim here therefore, was to project what nature’s curative forces are going to be, to restore the balance. Our aim therefore is to enhance or harness those very same forces which she used in her restoration while at times coercing nature into a slightly different direction or pace.
The one thing that must be conveyed before we delve any further is organics is more profitable, far more satisfying and far more healthier for both the grower and the consumer. Not just the food being grown but the working conditions are cleaner and safer along with the environment impacts being lessened or even negated all together. Everyone benefits, from the farmers inputs being softer, friendlier, safer to use, the food being free of all toxic herbicides, insecticides, fungicides, and hazardous byproduct chemicals like buriet and cadmium.
My personal experiences are in the field of Citrus, ducks with some vegetable seed production and earlier in the nursery trade growing ferns. So becoming organic was a matter of choice for my family, to produce healthy foods and a healthy environment or to continually contribute to the woes of the environment. My family was heavily involved in sport so we took a strong interest in health. Money was not even a consideration and had absolutely no influence our decision to produce organically. If we made a comparable living with organics everything would materialize in itself for the better. – Better health, a cleaner environment and a happier, healthier life style.
When we started our venture into organics 45 years ago there was no one to call on just a few people interested in holding onto traditional methods and ideas while trying to avoid the hazardous chemicals that were slowly gaining a name for being detrimental to both the environment and peoples health. Chemicals like DDT, Arsenic, organochlorins have since been banned, Hexane which is still widely used in the separation of soy protein products is banned in all Organic soy products. (http//www.docin.com/p-483617514html) The list is much longer and is getting longer as every year another product is found to be carcinogenic or contains chemicals that are hazardous to health and the environment.
I often said, “The main barriers we face in increasing the awareness of organics in Australia was the lack of media personnel, industrial might of those manufacturing the toxic chemicals, the lack of good quality information and the fractionalization of those farmers wanting change in distance, types of crops grown and politics.”
Quality information was scant with no direction, often with irrelevant information, The ease of readily available access to good reliable quality information was virtually nonexistent. Coupled with no experienced organic agricultural advisors to assist farmers wanting change and no government departments willing to support organic practices or policies the industry of change was always going to be long and arduous. There were no markets in place, no certification bodies, no standards, no money and no will except for those directly affected. The green movement was in its infancy and was virtually ineffectual while the basically multinational suppliers were ready to capitalize on all the above backed by corporate dollars and twisted facts of confusion and lies.
This was all about to change over a few strawberries and a very wet, wet season extending into winter. While expanding our Nursery, our cash crop of strawberries and silver beet were suffering from downy mildew. The solution was to spray every week with mancozeb. No problem here only that the withholding period was 4 days and we had to pick every second or third day. I enquired how do farmers overcome this problem? The answer was “DO NOT WORRY ABOUT IT NO ONE ELSE DOES.” Shocked and horrified I wondered how many products had the same answer to overcoming toxins or was all our food laced with chemicals?
Alarm bells are ringing with confirmation quickly answering my question that Australian food which included Queensland food was laced with poison. Listening to the ABC’s Brisbane market report that week I was surprised to hear that approximately 8mm of the food tested the previous month had chemical levels well above the recommended levels, while a further 15mm had levels above the recommended levels and in over 60mm of the produce tested traces of chemical herbicides, insecticides and fungicides were detected. It had to be noted that the word “Recommended” was used meaning that the food was still acceptable with toxic chemicals but not recommended for human consumption at these levels. The fresh food needn’t have inputs listed as manufactured food must have now days. This report will stay with me for the rest of my life that all is not well in the GARDEN of EDEN or should I say the chemically produced produce.
My conscience along with my environmental views had changed for ever. A new way had to be found. If there were no organizations then I would go it alone.
Another argument that often arises is that organic food is no different to chemically produced foods. The following 149 pages will certainly dispel that view of “Organic food.” Organic food is far, far more environmentally sustainable, the workers and producers are far more aware and healthier as a result of not being exposed to toxic substances. And for the food, well don’t take my word for it look at the independent research that has been done from around the world by biologists, chemists, biochemists and dieticians. They all agree and it does not matter, how you research it, Organic food is better for you, better for the farm, better for the environment and is the only sustainable way to grow not just your food but your clothes and energy.
Magkos F et al (2006) Organic food: buying more safety or just peace of mind? A critical review of the literature Crit Rev Food Sci Nutr 46(1) Pages 23 to 56. “The amount of nitrogen content in certain vegetables, especially green leafy vegetables and tubers, has been found to be lower when grown organically as compared to conventionally grown crops.” Nitrates increase the water content without increasing the vitamin and mineral content as the nitrates act as a saturated solution preventing the production of the vitamins and minerals in a balanced manner.
The 2012 meta-analysis “determined that detectable (organically accepted residues like pyrethrum or vegetable oils, not highly toxic chemicals) pesticide residues were found in 7mm of organic produce samples while 38mm (Toxic chemicals) of conventional produce sampled contained detectable pesticide residues.” This is of great concern and proves that even today like my experience 45 years ago; where toxic residues were detected in 60mm of the produce tested, still exist in the human and environmental food chain.
A 2014 meta-analysis “found of 343 independent studies, all found that organically grown crops had 17mm higher concentrations of polyphenols than conventionally grown crops. Concentrations of phenolic acids, flavanones, stilbenes, flavones, flavanols and anthocyanins were elevated with flavanones being 69mm higher.” (These are the technical names for many of the common vitamins and minerals)
Amazing that 343 out of 343 independent studies worldwide unanimously found that minerals and vitamins were at higher levels when the crops were grown organically. This is despite the arguments pedalled by farm input companies to the contrary that there is no evidence that Organic food is better for you. It would be reasonable to deduce that some of these reports were commissioned by the chemical producers or that their own research uncovered similar results but have never been made public. This is not to say that every fruit and vegetable had higher levels of every vitamin and mineral as one or two may be lower in a specific food item. I am dealing with facts 100mm facts.
As organic foods contain higher levels of vitamins and minerals it is relatively safe to state that they would be better for you and the human body would require less food to sustain a healthy body. On a personal level I eat two meals a day and run 3 to 5 kilometers six days a week. In the past I have run marathons and participated in charity runs and rides up to 480 kilometers and over periods of 24 hours plus covering very long distances at the same time. (during ultramarathons I would eat and drink continuously throughout the run.)
Barański, M; Srednicka-Tober, D; Volakakis, N; Seal, C; Sanderson, R; Stewart, GB; Benbrook, C; Biavati, B; Markellou, E; Giotis, C; Gromadzka-Ostrowska, J; Rembiałkowska, E; Skwarło-Sońta, K; Tahvonen, R; Janovská, D; Niggli, U; Nicot, P; Leifert, C (Jun 26, 2014). A systematic literature review and meta-analyses.
The British journal of nutrition 112 (5): pages 1 to 18.“Found higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops:” Again the evidence through independent analysis and research contradicts the lies and fallacies that there is no evidence to prove organic food is no better for you than chemically produced food.
I make no apology for utilizing in part the layout as used in “Organic”
Citrus – A Growers Manual” by David Madge as it covers nearly every aspect of the issues involved in growing organically to the present day. It was written nearly 20 years to the day after we established our Orchard at Nana Glen. The information parallels in many cases our own experiences and if it was available 20 years earlier we would have been able to save our selves many learning experiences at the time. We have included many practical examples of experiences we were confronted with and how we met the challenges at the time. Today there are many more departments to turn to for assistance and growers eager to help new producers and producers in conversion.
More information with a full list of useful information is available from their Web Site.
www.rirdc.gov.au or phone 1300 6343 13
The facts that have been used come from our own personal experiences in the Nursery, then later in our orchard, the growing of vegetable and flowers for seed with the Kaki Campbel ducks as our natural weed control employees and fertilizer spreaders.
Organics is a Way of Life which involves Living with & Using Nature Not Opposing Nature at Every Turn
The One Straw Revolution by Masanobu Fukuoka along with F.A.King’s book Farmers of Forty Centuries along with several other publications opened the door. “If I was determined enough, strong enough and resilient enough I would succeed. As an individual the movement would expand outwards from the individual as others come in contact with the individual the movement would spread.”
Years would pass before I again read these books analysing every aspect and applying what was read to my own orchard as Masanobu Fukuoka had done. The harvest figures by King when he compared the results of the Sichuan and Yunan farmers a century before were consistent or higher than production figures procured today. With all the sophisticated methods, new fertilizers, insecticides, herbicides and fungicides production figures were down despite what we were being led to believe. The figures from King were enough to tell me that we were seriously being lied to conned into buying things we did not really need. Toxic poisons that were conjured up to solve problems that could easily be solved by looking at history and nature instead of lining the pockets of a few multinationals. Governments at all levels were having toxic poisons foisted upon them with media campaigns urging approvals. Governments were given samples and told the benefits without questioning the hazards or if they did the questions were often superficial and approvals were given. The later withdrawal of many toxic chemicals like Arsenic, DDT, organochlorins and the like all added weight to the underestimation of the hazards and the overestimation of the benefits. Somewhere in the chain of events approvals were given when they should have clearly been rejected.
Restoring the health of agriculture is of paramount importance not just for the health of those workers on the farms but those workers in the cities and the environment. All are interconnected and it all starts at the farm, the sun, the water and the soil. Lets pass them on to the next person in a pristine state as they move down and along the food chain.
What exactly is organics?
Foods that are certified organic must be grown, handled, and produced according to the guidelines in place with the farm satisfying all the requirements set by the particular country that certifies them. Products must be labeled with the certifiers logo and code to confirm certification for the consumer.
It is illegal to call food or cosmetics Organic unless it is certified organic. Growers can use the words grown without chemicals however this should be treated with some suspicion. Certified products will have their logo and the words “Certified, Organic and the country of origin” clearly marked.
Food can be sold as Under conversion to organics.
Understanding the definition of organic farming and production including value adding is essential to agricultural crops, horticultural crops, poultry, livestock and aquaculture products. The guidelines and principles of meeting these definitions must be applied to be considered organic and to maintain the organic principles throughout the course of value adding. Organic production is an intricate system that strives to maintain balance within the environment by eliminating all practices that are detrimental to humans, the animals and plants involved and the environment.
* The International Federation of Organic Agriculture Movements (IFOAM) defines organic agriculture as “Utilizing both traditional and scientific knowledge, organic agricultural systems rely on ecosystem management rather than external agricultural inputs. It is a system that excludes the use of synthetic inputs, such as synthetic fertilizers and pesticides, veterinary drugs, genetically modified seeds and breeds, preservatives, additives and irradiation. Organic agriculture is a holistic production management system which promotes and enhances agro-ecosystem health, including biodiversity, biological cycles, and soil biological activity. It emphasizes the use of management practices in preference to the use of off-farm inputs, taking into account that regional conditions require locally adapted systems.”
It is imperative that growers understand and accept that organic farming is simply not about utilizing different inputs but it involves a system which is designed to minimize the need for intervention. This was emphasized several times by Masanobu Fukuoka when he reiterates time and time again “it is more difficult to do nothing than to try and intervene.” Today with many organizations supplying bugs to assist farmers it is far more economical to monitor and release the appropriate bug into the environment short term while adapting the local environment to harbour the next round of predators long term.
The difficulty lies for the lay person in the translation of organics to the farm operation. While the organic standards and principles sound rather simple the complexities in transferring from chemicals to organics is far from simple. Nature needs time to reestablish itself to find that balance and to maintain that balance with minimal counterbalances and fluctuations. This is where global standards require local solutions which differs on the type crop grown, the type of soil, the climate, the topography, local environment and local government requirements. My position was made easier as; our 35 hectares with the surrounding state Forest land, we had a healthy environmental base to begin with. A natural predator base with water supplying this lifecycle with the energy to stay local.
Good managerial approaches with good monitoring skills will eventually eliminate all need for external inputs with nature supplying the balance. The information farmers require nowadays is more readily obtainable but needs to be accumulated and digested locally to your individual needs and requirements with lateral thinking and lateral perspectives.
Why become an Organic farmer?
* Probably the best reason for becoming an organic farmer is that far fewer Organic Farms go into receivership than any other enterprise in the western world. This is because members are guided on the best methods to develop a farm enterprise plan, using proven track records and the real cost of production is returned to the farmer in a value added form,
* Farmers do not rely on Government subsidies to survive with farms being more able to survive times of strong winds, extremes in temperatures and rainfall,
* Greater security knowing that annual production rates are more consistent. Farmers attain far better yields in low production years when prices are higher and slightly lower yields compared to chemically grown produce when production is high and prices are lower. Overall this means a better more even spread of income with Nett higher yields.
* Greater Satisfaction that you are not contributing to the demise of the planet’s environment,
* The need of a healthier safer workplace and career.
Managerial approaches Differ on different systems
The beauty of organic agriculture is that it offers every individual a chance to express their individuality in management.Every grower will have their own view on how an organic farm, orchard, plantation or station should function. Lateral thinking created by the individual utilizing the individual property characteristics is what will define your final enterprise. I have always maintained that “I HAVE NEVER HAD A PROBLEM IN MY NURSERY OR ON MY FARM. I HAVE ONLY EVER BEEN CONFRONTED WITH LEARNING EXPERIENCES OR EXPERIENCES WHICH I HAVE LEARNED FROM.” IF this train of thought is maintained by all then life will be full of extraordinarily wonderful experiences. By enlarge The farmer needs to focus his or her attention on monitoring and how the natural system is evolving in his or her locality and surrounding environment. After fully understanding the natural and cyclic states of the transitions the farm is undergoing can a conscious plan to maximize the natural resilience of nature be incorporated with the view to entice nature’s natural productivity into your particular agricultural systems.
Farms are ecosystems
When we decided to establish our citrus orchard we had made a conscience decision to change the ecosystem within a section of the property. The orchard would change the barren, open weedy grass land flat, the new dam would compromise the seasonally dry creek bed to a 2 hectare wet land and the surrounding eucalyptus dry rainforest soils would be inevitably modified due to increased water holding capacity and an upheaval in microbiology. This increase in soil organisms would lead to an increase in small macro organisms like slugs, beetles, thrips mites, birds, reptiles all competing for top position until a disorderly balance is reached. The direct affects along with possible flow on affects all had to be considered prior to reaching a decision on what type of organic enterprise would best suit our property. In the end we decided to start with a permaculture system and move to a system that encumbered both permaculture and agroecology principles.
Permaculture
To what extent Australia can claim that permaculture was conceived here is debatable but what is known it certainly gained wide acceptance amongst back yard gardeners and hippies during the 1970’s and has since spread internationally. There is no doubt that Bill Mollison has done a great deal in promoting the benefits of Permaculture as an alternative structure in agriculture to using hazardous chemicals.
I believe permaculture has a place in every small medium and possibly large garden but becomes disproportionately unwielding on an agricultural scale especially where broad acerage crops are sought. Permaculture involves the deliberate choice and arrangement of the various components of an ecosystem system on a small scale incorporating the four tiers within a forest. The upper canopy, the middle branches, the soil surface and sub surface all working together in harmony.
* Permaculture certainly is a productive ecosystems which has diversity, stability and resilience of natures ecosystems all bound into one area. Permaculture is the harmonious integration of the surrounding landscapes, vegetables, fiber and food all grown and provided in a sustainable manner with all 4 tiers in operation. The spiritual needs of the person are fulfilled in a sense of complete balance. Practically though a family would need about 0.6 hectares of arable land to be completely at one with the earth and nature.
https://thefarm.com.au/whatson/living-agroecology-immersive-august-november-2021 Here we see the use of multi cropping between the main crop. We utilised 200 ducks for eggs on our citrus orchard.
The five things that are common amongst permaculturalists is the number of men who support beards, the number of women who support long natural tresses, their age is generally younger than most farmers and their enthusiasm, optimism and their willingness to help others, is embroiling as is seen here from this group of young Byron Bay farmers.
Agroecology
Agroecology was what we envisaged and fostered long term with a 3 tier system. While the upper canopy functioned well producing fruit, the middle branches did not support a diverse range of orchids, ferns and the like to be note worthiness, the soil surface was limited to grasses, legumes, ducks, wallabies with a wide range of invertebrates. It was the sub surface that sustained the maximum diversity of micro organisms, macro organisms, micronutrients and macro nutrients. The surrounding forests certainly improved dramatically as a result of the farming practices with all 4 tiers being very apparent by the time the orchard was fully functional.
Agroecology is an ecologically based agricultural system which incorporates all the integral interactions between all the individual components within the system so that a synergistic affect is directed throughout the system. Despite minimal use of machinery, the purchase of trace minerals through crushed black basalt rocks and sawdust, it was the biological processes that were set up that became the indispensible driving force that provided the energy to sustain the orchard’s full production at minimal costs and effort.
Agroecology is a biological discipline that uses ecological theories to monitor and evaluate agricultural systems so that they are productive but are also resource conservative. Agroecology is concerned with the sustainability and productiveness of the agriculture sector so that sustained yields are maintained which optimize the use of local natural resources while minimizing the negative environmental and socio economic impacts of their operation as opposed to modern farming enterprises which have succumbed to synthetic fertilizers, synthetic herbicides and toxic chemical insecticides along with the poorly thought out technologies designed and incorporated by multinational organizations whose major interest is that of their share holders.
It is impossible to consider agricultural production separate from environmental issues. “Nature’s economy shall be the base for our own, for it is immutable, but ours is secondary. An economist without knowledge of nature is therefore like a physicist without knowledge of mathematics.” Carolus Linnaeus.
I suppose the same could be said for agriculture and the environment but more so as they are both extensively intertwined. Agroecological approaches this because it is more sensitive to the complexities of local agriculture, and has a broad performance criteria which includes properties of ecological sustainability, food security, economic viability, resource conservation and social equity coupled with better methodologies for increased production rates.
For agroecological technologies to work in practice they require technological innovations, more profound agriculture environmental policies, socio economic changes and more profound understanding of the complex long term interactions among resources, people and their environment. To attain this level of understanding agriculturalists must cease the denials and conceive the ideas that ecological systems and agricultural systems are both one in the same and to the same extent that human dominated socio economic systems can also be incorporated into the overall plan. In other words the three are inseparable however the latter must be drastically limited in the near future.
It becomes extremely relevant therefore that agroecologists:
* Work steadily towards enhancing the recycling of biomass and optimizing nutrient availability and balancing nutrient throughout the farm,
* Work towards improving field conditions so that maximum soil biomass is actively created throughout the soil to maximum depths,
* Work towards maximizing soil cover – Carbon sequestration by maximizing solar radiation, air and water within the surface and subsurface microclimates,
* work towards enhancing the beneficial biological interactions and synergisms that normally work within the 4 tiers of a healthy viable ecosystem.
Biodynamics
Biodynamic agriculture is based on teachings by the Austrian philosopher Rudolf Steiner in the 1920’s. Steiner believed that soil, plants, animals; including humans and the universe of the sun, moon, water and soil are all intimately interconnected. Enhancing the synergism of each is an important criteria for establishing healthy soil, water and air which lead to healthy plants and healthy animals.
The Bio dynamic approach involves a strong commitment to its philosophies which includes the use of special soil, compost and plant health preparations referred to as BD500 preparation. Careful attention is given to the time of preparation planting and usage of the BD500 formula on the farm through the phases of the moon and seasons.
An in depth knowledge and faith in the system is warranted to gain the maximum advantages of the system.
To add weight to the Steiner theories the Chinese were farming using the moon and sun cycles with special compost methods when planting over 4000 years ago. The Chinese calendar is based on the lunar cycle. I hope to recover some old photos I have stored away of rock carvings tabulating agriculture from near Yueliang (月亮) east of Kunming. The information given to me is that they are over 3000 years old telling the story of the sowing and harvest seasons based on the moon and the sun.
All our vegetable and flower seeds were sown based on the annual BD moon calendar. While I had not collected data from the field the crops we sowed were all successful.
Before we look at what is required to be not just a good Organic Grower but a Successful Organic Grower lets look at the farm as a parcel of land to be integrated with nature. There are many aspects to be looked at when buying a parcel of land for a farm or buying an existing farm.
Established farms with improvements, machinery and other items including sheds, dams, roads and trees in orchards etc can usually be bought as a parcel well below their replacement cost. Of coarse the machinery is second hand fencing may need repairing pumps need cleaning, upgrading and what chemicals have been previously used, all have to be taken into consideration but starting from scratch is total and usually with all new modern equipment and modern technology.
Buying a bare parcel has the advantage that an overall plan can be incorporated from the begining. Buying an existing establishment has the advantages of the previous owners input knowledge and of coarse the previous owners mistakes. Which way you go is up to you but lets look at some of the positives and negatives further when considering a purchase.
Location
The location for transporting the end product to market has a huge impact on a farm, orchard or nursery. For us based outside Brisbane half way the Gold Coast was ideal for the Nursery as it was within a couple of hours delivery to most our markets the retail nurseries. The position of the orchard half way between Coffs Harbour and Grafton again was ideal for transport to both the Sydney, Brisbane and Melbourne markets and there were 3 major transport companies to tap into for competitive pricing.
The nursery would have been hopelessly placed outside Coffs Harbour as would have been the Orchard in Carbrook. It would have been impossible to transport the quantities to Brisbane market let alone trying to service Sydney or Melbourne without buying a truck.
Location Affects Climate & Microclimate
Climate strongly influences pests, diseases and weeds. High rainfall areas east of the Great Dividing Range accounts for most the disease and weed pressures experienced by producers. Compared to drier inland areas which are warmer and dry often with dusty conditions which are more conducive to red scale and spider mite type infestations. To use mandarins as an example hot dry conditions are not conducive for good fruit set but are excellent for fungal disease eradication.
Microclimates on a property near the coast that are airy will help eliminate symptoms of Septoria and Anthracnose. Both these fungi are more prevalent on fruit which has been exposed to cool moist or frosty conditions following fruit set.
Soil type
The soil is one of the two most critical resources the farmer has at his disposal which will determine whether he succeeds or fails and by succeed I mean fulfils his ambitions on the land. The soil type needs to be ideal for his venture with some scope for maneuvering to other crops if need be in the future. The soil for a citrus producers are ideal if they are:
* Well drained light gritty clays on a gentle northerly slope are best. Poorly drained heavy clays are far more susceptible to phytophthora and other root rot diseases for which there are no real organic solutions at the present time,
* Light sandy soils of low fertility require extensive quantities of high quality organic matter and nutrient additives to secure good growth and maintain good water retention which can be achieved,
* Neutral soils with pH values between 6.5pH and 6.7pH are best as low pH and high pH soils often run the risk of nutrient supply deficiencies or toxicities which require better managerial skills and experience to overcome.
Weed Status
Avoiding land that is infested with weeds of one type or another is near impossible but try to avoid those lands which have problematic and difficult weeds like Parramatta grass, Sporobolus africanus and fire weed Senecio sp. which are good examples of this type of infestation which takes time and effort to suppress or eradicate properly so the farms full potential is available. Given the cost effectiveness of organic herbicides being rather poor and the fact that organic certifiers discourage excessive cultivation, hand removal or long term soil improvement and beneficial green manure competition are the only real methods of control and suppression.
External Infection/Infestation Sources
Isolation or natural borders of mixed native vegetation offers the mixed farmer the best chances of alleviating pest infestation, fungal outbreaks and weed anomalies. A new farming venture flanked by natural swathes of mixed native vegetation will by way of natural air currents eliminate weed seed deposition and fungal spore barriers and harbour predatory pest control.
Contamination risks
Many organic farms are impacted by the contamination deposits from surrounding farms which is an ongoing concern to their organic status. The present and potential future contamination risks should be taken into account during site selection. A friend of mine was always worried by a Copper Arsenic Pole treatment plant which the council approved on an adjacent property. He voiced his opinions very strongly with the assistance of other organic growers and certifiers to no avail. As the fall of land was away from his property the council did not consider fire, fumes or road accidents as reasons for rejecting the project but placed growers at additional risk. The risks here were inherited after his decisions were made and had the potential of ruining his enterprise. Fortunately today there is a greater awareness of the problems faced by organic growers and the environment. Risks however will always be higher adjacent to industrial areas and intensive horticulture zones compared to land situated adjacent to natural bushland National Parks and forestry.
Farm Layouts
Several aspects of farm design relate specifically to weed, disease
and pest management. These are covered later. Other aspects to consider are:
* Row orientation will depend ultimately on the topography of the land the property aspect whether it faces north or another direction and the crops envisaged to be grown. The need to consider whether orchard trees will grown as a hedge row or spaced wide enough for individual trees to expand. Hedgerows inevitably need to be planted in a north south orientation to gain the maximum amount of daily sunlight and are better on northerly or north westerly slopes. Trees widely spaced will also prefer a northerly sloping aspect but the row allignment is not as critical. Widely spaced trees allow for better sunlight access to all the foliage, better air flow around each tree with the inter row cover crops yielding greater volumes of organic matter for the trees.
On farms with steeper slopes it will be necessary to control soil erosion with cross contour planting and cross ripping even if vegetable or flower beds are deployed to manage erosion and to capture as much of the excess runoff as possible.
* Irrigation system types vary greatly on the enterprise. Most orchards would deploy drip irrigation or micro jet irrigation as it gives the orchardist greater control over water in every section of the orchard down to the individual trees, coupled with high efficiency in controlling soil moisture levels in the tree root zone. We used micro jets with jets that allowed for different flow rates beneath different trees. The biggest problem with micro jets are ants during prolonged wet periods. This meant that that the ends of the lines had to be opened up to allow flushing before each use after a wet period otherwise we would spend all day cleaning out blocked jets. This was quickly learnt from experience. The use of micro jets allowed us to capture more water through fogs which created convectional eddies throughout the orchard. Fogs were common thus reducing the quantity of water being used and pumped while at the same time increased the quality of the water being supplied. Using water in this manner also had the benefit of reducing collective salt levels which may accumulate from the continual use of dam water or underground reserves. Irrigation was carried out during the late evening and lasted most the night.
Drip lines are virtually ant proof but are subject to less efficiency as larger pumps are required to service large areas and visual observation of the drips is far more difficult where cover crops are being grown and are time consuming.
On mixed vegetable and flower farm irrigation usually deploy sprinklers which cover several beds at a time in a rectangular pattern. Our vegetable flower beds were covered using 15 meter circular and semi circular sprinklers. Again watering was done in the evenings to prevent evaporation and to capitalize on any fogs that descended in the evening.
Many of the larger farms of today deploy Travelling Irrigators which rely on level land, very large water supplies and large pumps to drive the wheels.
* Field maintenance efficiency was of great importance to us as we started from scratch and wanted to employ the best that was available for efficiency because that meant lower environmental degradation. Having the opportunity to visit other orchards in the district allowed us to communicate with orchardists, managers and cooperatives (Johnson’s blue berry farms) seeking out what worked from what was inefficient for small operators or defunct (Johnson’s stone fruit orchards). It also allowed us to compare the different types of farms and orchards in a very impartial way. This was played out further following my second trip to China and living with the Yizu where we learnt the real need and efficiencies of running animals for weed control, the need for hand labour with direct action rather than looking for the alternative in machinery which we have become so accustomed to.
Field maintenance efficiency is the theoretical time required for the various maintenance tasks to be carried out and the actual time taken to carry out the tasks. The actual time taken to carry out the tasks includes travelling time, refueling, rest breaks and overlapping of slashing passes or plowing or disking times.
The farm layout is paramount in the final efficiency of the farm operations. A good layout saves money on energy inputs for tractors, pumping, heating or cooling, labour, soil compaction, erosion control, picking and packing and ease of assembling the items required on a daily basis.
* Risk management in conversion was not an issue for us as we started from scratch. I believe that there is some risk in converting from chemical to organic production. Conversion requires the grower to be confident in thinking outside the square and adopting new management practices well entrenched over the years or even from generation to generation. They may not be familiar with many of the practices, terms or have good working biological skills. Conversion as I have said on many occasions is like a sick patient who has been accustom to taking medication on a regular basis or drugs there is a period where withdrawal symptoms take over and everything appears to be going wrong. Like a sick child your offspring need special care and time to overcome the difficulties.
From the start I am assuming that the farm was one that had relied wholly on toxic chemicals. It must be considered that the farm relied on cheaper soluble fertilizers that introduced Nitrogen, phosphorous and potassium all above what was required like sugars and fats in the human diet. The soil does not have the capacity to store or produce a nutrient cycle within the soil biologically.
The farm is totally reliant on toxic chemical herbicides and with bare earth policy to control weeds or best has a monoculture mentality that will fix all.
The farm is totally reliant on expensive pesticides in a bottle and has no or very small areas to habour and protect predatory organisms so that biological control is sourced naturally on the farm itself. This usually means a weaning period using substitute fertilizers and pesticides until a fully integrated predatory ecosystem can be incorporated into the farm plan and is self productive.
Instead of the quick temporary fix organics relies on the long term fundamental understanding that nature will provide everything the farm needs to survive and thrive. It is this time period of withdrawal; like a new born athlete, he must first rid the body of the fats and simple sugars that dominate his body while at the same time commence a training programme that will lead to stardom. It wont happen overnight but like our athlete if he just jogs around the track at 8 kilometres an hour for half an hour he will never run a marathon at 20 kilometres an hour for over 2 hours. “Like a marathon runner the converted organic farm has to last the distance with the lowest inputs yet needs to produce the best results year after year.”
We achieved the farm that produced a biologically active soil, utilized slow released nutrients at a rate the plants required within a soil that has great buffering affects against disease and leaching.
We achieved the farm that produced cover crops and mulch or was grazed by productive soil microorganisms worms and poultry to keep weeds in check or is lightly slashed to reduce weeds and to produce green matter that is biologically active and nutrient rich.
We can achieve the farm that is monitored, releasing and producing its own predatory organisms to keep past problematic organisms in check. This usually includes the less expensive release of predatory organisms to balance and assist in the local species to gain control.
The two biggest risks to production that I am often asked how to control in conversion are:
* How do I control weeds with fewer hours, materials or specialised equipment to replace my herbicide usage,
* How do I offset reduced production levels as a result of direct competition from weeds and the reduction or cessation of chemical fertilizer inputs or soil improvement to replace a nutrition program
based on water soluble fertilizers.
Growers need to manage their affairs properly ahead of the transitional period to avoid disappointment and disaster. For example an orchardist can for a single year commence the production of high quality mulch with Blood and Bone with Crusher Dust. This can then be spread beneath the trees at a thickness of 70mm to 100mm in thickness with a spattering over the rest of the orchard along the inter rows. In the mean time the inter rows can be sown with a variety of climatic suitable annuals like clover, rye, wheat and other annual grasses. In this manner the farm and trees are gaining the biological balance they require with the excess nutrients being buffered in the soil, while microorganisms and worm activity are multiplying rapidly.
With vegetables and flowers a 20mm to 40mm layer can be spread over the beds. The farm can be fertilized with a reduced level of synthetic fertilizers in the first year while the mulches are again applied in the second year without further need of synthetic fertilizers.
https://www.kobo.com/au/en/ebook/the-organic-farming-manual-2
Knowledge is always valuable and cannot be priced.
What is required to be not just a good Organic Grower
But a Successful Organic Grower – The Livestock
In the past animals always played an integral role on the farm. Even today with the intensive farming practices resorted to in Asian countries animals like poultry, pigs, goats and rodents are used to recycle nutrients, weed control and pest management and income diversification. Unfortunately animals on farms like animals in the west are being displaced by chemical fertilizers, herbicides and pesticides which are moving from mixed agrocological farms to specialised unsustainable toxic enterprises. These toxic additives cost money to buy and cost money and time to prepare and use, where as the animals produce an income. Livestock particularly poultry can be practically managed with the reintegration into organic farms yielding many benefits. These benefits include:
* The development of greater diversity with returns,
* The diversification of chores relieving boredom,
* The value in farm stays increase dramatically with livestock wandering around,
* Grazing animals especially poultry contribute extensively to existing weed management programs and are highly espoused by the certifiers as weed control managers. We noted that our ducks saved us 50mm in slashing costs, corresponding maintenance and 4 hours a week on average in slashing time and maintenance.
* Grazing animals converted weeds and recycled nutrients on site distributing the nutrients around the trees. This was governed by the placement of feeding containers and water.
* Income diversification with weed control was the main reason we adopted poultry in the orchard.
* The control of movement and stocking grazing needs should be carefully considered to avoid patch grazing and better insect control.
Managing the movement of poultry is as easy as strategically placing several watering stations throughout the orchard prior to releasing them in the morning and making the birds find it themselves. As they wonder around to find the new locations for the water they eat and fertilize. What we found the ducks split into 8 groups each with 40 to 60 birds and each would find a separate water station to settle near where they further split into smaller groups of 8 to 12 birds. Mind you we did keep 1 drake to 50 ducks. Lucky duck ah drake!!
Poultry
What is the Best Method of Pest Control? – Ducks, Geese, Guinea Fowl, Turkeys or Chickens?
Chickens in an organic orchard https://www.phillyorchards.org/2015/10/06/poultry-in-orchards/
Most smaller landholders that consider animals in a mixed farming enterprise inevitably turn to poultry. My choice involved looking at barren earth with very little cover except for the noxious weed Parramatta Grass Sporobolis africanus some slender tufts of the native grasses like Kangaroo Grass Themeda australis and some scattered tufts of Paspalum paspalidium criniforme with groundsel Senicio madacasiensis and scattered Scotch Thistle. The ground was hard with little top soil. We envisaged greater growth in the following months as we were considering lightly disking the area. (This was a mistake as deep cross ripping proved to be far better solution when we reforested 3 hectares further up the hill.)
The advantages particularly in an orchard apart from what has been mentioned above are numerous. Poultry produce a nutrient rich manure and with many of the commercial organic citrus fertilizers being based on composted poultry manure they were shaping up as the natural ideal choice.
The next thing to consider was the habits of the different forms of poultry available. Geese were larger and consumed large volumes of grass compared to Guinea Fowl Ducks and chickens. Chickens were seen to be poorer grazers but good insect, small rodent and reptile hunters while scratching all day. The scratching habit making hollows in the ground was out, especially if we were unable to control the birds around the trees without going to great expense. In this regard Guiney Fowl were far more attractive.
The ducks we thought had far better prospective, as they were good graziers eating most grasses and sweet herbs they came across. They were also known to be good scavengers feasting on slugs which were plentiful along the creek and possibly in the orchard. They like chickens were known to eat mice and small reptiles but had the advantage of eating citrus spoils and rotten fruit including oranges. This was appealing in the light that neighbours had problems with fruit fly. The only problem we fore saw was the dam. If they found water that is where they would spend most the day. Fortunately the dam was 100 meters away and there was the new forested area being developed as a buffer zone.
Added to this ducks were excellent egg layers provided they were not upset. Our choice was made then to buy 400 Kaki Campbells to roam over 2 hectares well below the 1000 birds a hectare allowed by the standards. As it turned out our 400 ducks returned 200 dozen eggs a week when laying. Another advantage of the ducks was that they all lay within an hour of sunrise meaning the eggs were all collected before they were fed and let out in the morning. Our biggest problem was finding a market for the eggs as no real market had been developed and no organic duck eggs were on the market when we started.
* There are also some disadvantages particularly if the fowls are roaming and vegetables are involved. We went down to the beach one fine day and on our return the ducks were very happy with their afternoons work. They located a hole in the fence and found the peas and Wong Bok Cabbage much to their liking but not ours. Nothing could be saved and their little arses almost ended up in the freezer.
* Protection from predators like foxes, dogs and larger carpet snakes were always a concern. The ducks quickly adapted to our two little Fox Terriers who were there to protect the ducks and to keep rats and mice at bay. Despite foxes being prevalent in the district the scent of the Fox Terriers at night and their presence during the day seemed to be enough to deter them.
* Carpet snakes were difficult to control and the duck house saw at least 2 visits a year with the loss of 1 to 3 ducks before the culprits were caught and relocated. The presence were enough to send many of the ducks off the lay for around 10 days.
Small Time, Adjunct Poultry Management
require special needs:
Grazing poultry with in the orchard or farm requires additional time and preparation. Feeding stations need to be moved daily in orchards to ensure the birds move around and cover the whole area. Our orchard was free of all fencing in this regard except around the 1 hectare for growing vegetable and flower seeds. Runs need to be organized on so that the birds can run in safety to the exclusion of dogs and foxes. Water and feed stations need to be plentiful and kept clean on a daily or weekly basis. Ducks have an uncanny way to mess and dirty every water station every day.
Permanent or mobile housing and yards?
* Permanent housing is easier to establish with regards to such aspects as water supply and fox proofing.
* Fences and gates need to be designed to allow ingress and egress points for machinery and workers yet be fox and dog proof.
* Manure deposits and ground cover disturbance are concentrated around the housing but can be managed easily if the housing is closed for access during the day and watering stations provided throughout the orchard or farm. Similar moves would need to be considered in a vegetable garden scenario.
* Mobile housing avoids the congregating problems provided water is available. The biggest problem is the expense attached to the original set up.
* Mobile housing, fencing is an additional problem and relies on staff moving the housing or fencing regularly depending on the crop.
The next Step
Certification & standards
Once you have decided which type of farm you want to develop or buy and how you will modify it to suit your preferred organic model you may ask what is required for certification. How do I go about getting certified, what are the advantages to being certified and when is the best time for applying for certification?
Accreditation is required for all organic food sold in Australia and no food, clothing or cosmetic line can be sold or marketed as organic without accreditation. It is a standard designed to ensure the public that the product is not just certified organic but the grower and manufacturers adhere to the strict guidelines in every stage of production of the produce along with their environmental responsibilities are met.
Certification is a perquisite for any grower or manufacturer who wants to export their products as organic.
Advantages of being a certified member:
* Organic Certification can be looked at as a valuable resource for value adding farm produce which stands for safe food products, integrity and environmental credibility,
* Helps promote the product on a national and international scale,
* Assistance and training with seminars are organized for the benefit of members,
* Meet local growers who may have had similar experiences,
* It provides more choice of products and maintains quality in the industry. It gives consumers more choice and a broader range of products at a uniform quality to select from,
* Easier for organizations to gain political representation,
* Standards make life easier,
* Organic products are presently in high demand both locally and overseas and have been for 3 decades and are expected to continue to be in high demand well into the future. China is seen as a huge organic market ready to be exploited.
And the disadvantages are:
* Usually poor communication skills from certifying bodies,
* Greater reliance on individual producers for help and assistance.
When is the best time for applying for certification?
You probably expect me to say now do it straight away but certification needs special consideration and timing is important. Several things need to be addressed first prior to making an application and these depend strongly on the property and the enterprise being undertaken.
“Learning from experience is costly while learning from another’s mistakes is wise.” We made this very mistake by rushing in and it cost me thousands of dollars when I could least afford it. We had finished planting the trees in section one and made our application to join NASA. The inspector came out and all was well with our documentation, property and plan. We had done our homework and plans were all in place. The mistake was we were paying for membership when the orchard was not in anyway in production nor would it be for several years. The first 3 years all our fruit was sold at the local market. Certification was costing us money with no return.
So think about it and plan entry for when is the most advantageous to you not when it suits the organization. As I found out later members would have assisted me for the three years until the trees reached a semi viable stage.
Review your properties strong points and weak points.
* Is it a neglected property that is in dire need of revitalization,
* Is it a property that has a history of chemicals and needs a transitional period,
* Is it virgin ground ready to be farmed for the first time,
* What is the nature of the enterprise being established on the property?
* How will past operations affect the present plan and crops?
All these factors along with the personal history of the property and enterprise being established should govern the entry time.
Further, organic certification is also about good management practices and good management practices include product knowledge from the seed to the consumer, good environmental skills and good forward planning whether it is a virgin property or a property in conversion a good property plan must be in place and include:
* All documentation should include time frames for each project to be undertaken especially where part of the property is undergoing conversion,
* If trial areas are to be tested first prior to looking at full conversion of the property. There needs to be a plan in place to show that organic and chemically grown produce will not become mixed at any stage during the trial,
* The establishment of windbreaks, revegetation of gullies creeks or riverbanks, cover crops and crop rotations would all need to be included,
* The use of inputs including mulches, possible uses of insecticides/ parasitic organisms, fungicides, weed control etc. for your enterprise,
* Specific problems of a property often includes the adjacent properties use and how their contamination may ultimately affect your enterprise. These include spray drift, water flow erosion, deforestation etc. while some can be addressed others cannot. A friend of mine who was banana farmer was refused certification because his neighbours used toxic chemicals and washed their equipment in a dam which overflowed onto his property. They refused to change their washing practices. Unfortunately he had no address on his neighbours short of buying them out.
How do I go about getting certified
First while things may look wielding and unapproachable in the short term, organics is no where as difficult as it first appears if taken one step at a time.
The first step in attaining certification is to contact one or more of the organizations mentioned below to find other growers in your district have a discussion then approach the certifying body/ies. Local organization/s will only be too willing to assist you and to locate local members to talk to.
The second step is to contact one of the organizations below which are permitted by AQIS to certify and request their standards and forms and go over them. Organic standards are available from the certifiers web sites. They outline all of the definitions, requirements, recommendations and restrictions regarding the practices and materials that can be used within certified organic production and processing systems. They also cover such aspects as the transport, storage and marketing of organic products away from chemical produce where ever possible.
Organic standards will briefly list the range of compounds which are permitted, restricted or prohibited for use to organic growers. Materials and substances not listed in the standards should be checked with your relevant certification organization as to whether they can or cannot be used. Sawdust while an acceptable product for mulch maybe excluded if it has traces of preservative in it or has been derived from a sensitive logging location. You need to notate what materials you have used and intend to use, using these lists.
Some countries, including key markets for Australian fruits like the USA, Japan, Malaysia and now China, have developed their own organic standards that must be met by produce exported into those countries. Australian certifiers can become accredited under these foreign standards. However, certified Australian producers are still required to complete extra documentation to satisfy the individual requirements of some of these standards. In China fruit must be free of fruit fly and come from fruit fly free zones. Which also includes possible contact with fruit from fruit fly zones. Irradiation is not acceptable form of fruit fly prevention. Be aware that you may be asked to supply produce for export which may involve more costs but maybe more financially viable. The dollar exchange rate at the time of sale must be considered and when exporting.
To achieve and maintain organic certification, growers must comply with the relevant countries standards while implementing them in a practical way that suits their particular enterprise.
Who can certify organic enterprises?
Organic certification in Australia is regulated by the AQIS Organic and
Bio Dynamic Program. AQIS accredits independent organizations to
operate organic certification schemes.
A list of Australian certifying Organizations with their contacts can be found at the bottom of this chapter with Organic agents and outlets.
Contact & application
After speaking to other growers form the various organizations obtain an application form from your preferred certification organization with the rules and fees which are applicable to your enterprise. The following steps need to be taken in the following order.
Copy of the applications form and questionnaires.
A list of requirements for Organic Standards for nassa can be found at
http://www.nasaa.com.au/data/pdfs/AAAAmm20NASAAmm20Organicmm20Standardmm2006-02-2012.pdf
Information pack re Organic Certification
http://www.nasaa.com.au/data/pdfs/F1mm2008mm20JASmm20CERTIFICATIONmm20INFORMATIONmm20PACK.pdf
Application form to proceed with an application from nassa
http://www.nasaa.com.au/data/pdfs/F1.03mm20NCOmm20JASmm20APPLICATIONmm20FORM.pdf
Application form from nassa to become a member proceed to Australian Producer application & Organic Management Plan.
While the forms are relatively easy to follow I had no, absolutely no feed back from questions I have asked nassa over the years either as a member in the early 1990’s or while writing this book. A copy of the forms with detailed infills would have been very helpful to members. I sincerely hope that their strategies have changed recently. Where as when I was a member of HGA I found them completely cooperative, grower friendly, offered assistance or referred me to other members who had similar operations that may have been able to assist. Unfortunately HGA merged with nassa several years ago and the old style laxness appears to still be the order of the day.
Questionnaire
The comprehensive questionnaire will be provided and needs to be filled out requesting information on the management of the enterprise to be certified. This includes past chemical use, cultivation practices, fertilizer inputs and other nutrient management strategies, pest control methods, crop types and rotations. The risk of chemical contamination from adjoining properties and other sources is also of interest. The questionnaire is to be completed and returned together with a map of the property clearly showing the location of areas to be certified. A statutory declaration will be required to be signed. This attests to the accuracy of the information supplied and adds some legitimacy to the certification and licensing process.
The completed application form and fee should be returned to the organization for consideration once you and your enterprise are competent that you can comply to the minimum standards.
Inspection
You will be contacted to arrange a visit by a professional inspector specially trained for the purpose of first going over the paperwork to check that everything is in order. He will assist you to fill out any sections that you may have had difficulty with and then verify that what is written is correct by asking relevant questions or inspecting the section answered.
Next the inspector will inspect the growing sites which have been mentioned noting all the above mentioned items including the common boundaries with neighbours.
At this stage the inspector will collect a number of soil samples and tissue samples from various locations on the farm. They will be tested for chemical residues and compared to what you have stated has been used. If you have recently used lime this should show up as higher than normal or higher than an adjacent plot which has not been limed. Any inconsistencies will need to be explained. Windbreaks and other programs associated with the farms overall performance.
The next stage will be an inspection of out buildings including tractor sheds, chemical storage shelters for those farms looking at conversion, packing sheds and facilities for storage etc.
Application review
The questionnaire, inspection report, soil tests, tissue analysis and produce test results will then be collated and reviewed by the certifying organization. The organization has 4 basic positions to take:
* Accept the application as it is and offer certification,
* Offer certification subject to minor changes,
* Defer the application requesting further information,
* Reject the application until certain objectives have been met which will be listed,
* Reject the application outright if there is good reason to do so with an explanation for the rejection.
Contract
If the application has been accepted, the applicant will be offered a contract of certification. The contract may include certain conditions as decreed necessary by the organization for the maintenance of certification.
Certification labels or logo may be required and used in accordance with the licensing body to promote the produce as certified and to readily identify it.
Withdrawal of the certification can be done if the grower breaches any of the standards.
Certification levels
Once certification has been granted the grower must adhere to the plan for conversion to meet their targets or maintain and continue to implement the standards which suits their particular enterprise. The different bodies have a minimum standard that needs to adhered to but welcomes growers to advance on these minimums whenever and wherever possible.
Organic standards are under constant review internationally and locally to keep abreast of modern technological advances within the industry. Organic certifiers say farmers are welcome and encouraged to prepare and furnish their certifiers with recommendations which will benefit the industry but farmers are not usually in a position to comment or put their views before the boards due to work commitments and travelling distances. Growers and manufacturers must keep abreast of any new regulations affecting their enterprise/s.
Presently there are 3 levels of certification that a grower has to proceed through:
* Pre certification which is a 12 month period which starts from the time the contract is signed. It is a period where the growers must demonstrate that they are proceeding forward with their plans to convert to organics or Bio dynamic farming. No claims can be made regarding the organic status of the enterprise or its products during this phase. The pre certification certificate has eliminated a small number of growers who had no intention of converting to organics but had sought to cover a crop that was about to be harvested capitalizing on higher prices. (Racketeers) I personally believe that this could be reduced to 6 months or timed to ensure the present crop is fully harvested prior to certification.
* In conversion commences immediately following the pre certification period and allows the produce to be marked “In Conversion to Organics or bio dynamics.” It implies that the grower has displayed a level of competency in managing a biological sustainable enterprise. Properties will remain in conversion for at least two years depending on the history of the enterprise and current management practices. It could last several years as it takes time to develop a good organic production system.
* Certified Organic or Biodynamic are the top levels of certification and allows the produce to be marked “Organic or Bio dynamic.” It implies that the grower has displayed full competency in managing a biological sustainable enterprise.
Annual audit
Once certification has been achieved, adherence to the standards is necessary to maintain full certification. The enterprise is re inspected annually with short notice.
Consider Marketing, Economic Aspects & Local Groups
Before applying for certification it is a good idea to acquaint yourself with any local Organic groups. When we were first certified 25 years ago organic organizations were very scarce on the ground. In fact in Coffs Harbour we had to set up our own organization. CROPO (Coffs Regional Organic Producers Organization) was conceived out of the need to collate information, broaden horizons bring producers together and disseminate information to the community at large. It was born by a nurseryman and myself beneath a large Eucalyptus signata out of desperation for information and over an ailing farming community where banana prices were depressed, stone fruit orchards were going broke and residential land was encroaching viable farm land.
At the inaugural meeting some 86 interested participants turned up to a meeting organized by the local Agricultural department. Growers from all enterprises turned up, some expressing the need for local growers and residents interested in organics to join an organization others out of curiosity.
It is important for organic growers and the community to gather as one because while it maybe expanding rapidly, the organic market is small and can be easily over supplied with certain products or can be directly affected from over supply in the chemically produced arena. This was typified during the mid 1990’s when banana prices collapsed with an oversupply in far north Queensland. It had repercussions in lowering the prices in all fruits not just bananas.
Market research is easily conducted through small groups like CROPO where both farmers and residential members mix. Part of our research using fruit size and prices was conducted at meetings. These family residents supplied crucial information to us in regards to the size of fruits preferred by different segments in the community. CROPO also pointed us in the direction of which native crops at the time had a better chance for early marketing and what locals would be prepared to pay for the product. Most members supplied the information freely. This is a most valuable resource that growers rarely take advantage of. I reported in another chapter how our agents phoned us and told us that the smaller mandarins were slow to sell and not to send any more. Yet 2 weeks later they were phoning and screaming in our ear to send more. The research paid off. We gave produce away at the end of the evening through the nightly door prize raffle to help maintain local; interest and enthusiasm to participate.
Racketeering and Organics
While Australian organic citrus sits on the cusp of expansion with a bright future in China our research here in China shows that Australian fruit and vegetables are seen as clean and green whether or not it is farmed organically. This may compromise organic marketing as such and will need to be addressed by those marketing Australian organic produce.
Many farmers markets in Australia supply food that is not grown organically but openly state that the food is grown organically. This practice is illegal and should be reported to the police as soon as it is observed if suspicious. No certification label or number means it is not organic.
The other problem here in China is that all organic food must display the official Chinese Organic Logo. This is not a problem in itself. The problem lies in the necessity which has arisen due to racketeering. As the organic industry is very small and organic prices are somewhat exorbitant fetching 4 to 6 times that of chemically grown food items. Chinese racketeers have been quick to jump on the ban wagon, buying good looking quality chemically grown food doing it up and selling it as organic. The government has clamped down and now only has one official Organic Logo. I believe this habit is not just widespread in China but throughout Asia. Friends have reported back from Thailand and South Korea reporting similar scams there as I explained here from China.
I lived and worked in china while writing the book so came face to face with it while researching different aspects. I have taken several photos and presented myself as an Australian inspector of organic produce to help stamp the racketeers out. Even department stores get involved. When ever I photograph the stores and produce, the labels are quickly removed along with all references to it being organic, until the following day. Any follow up visits I did was often received with special attention like being followed around the store and asked at every turn if there is anything they could help me with in particular until I finally left. At times I was privileged enough to be accompanied by the store manager. Again all references were conveniently removed as I approached the fresh fruit and vegetable sections or the fruit and vegetables were conveniently covered over with a sheet. i must thank the authorities for their assistance.
Another department store had signs erected at the entrances that “No photography was permitted within these premises without the prior knowledge and acceptance of the management.” Interesting that it was only in English. Must have ruffled a few feathers. That may have deterred me but did not stop the police from entering and gathering their own photos and evidence though.
Several stores have removed all references to organic permanently stating that they did not realize that all fruit and vegetables sold as organic had to be certified under the one logo in China. One store informed me that they were unable to access certified organic fruit and vegetables in Chong Qing as it was all sent to Beijing, Shanghai, Chengdu and Wuhan.
Large market access like China is very difficult for small operators and the need to form cooperatives or alliances with agents to exploit these niche opportunities will be paramount now and in the future. I certainly believe that there is a market in China a big market if properly worked through. Obviously many store owners and supermarkets consider there is as well.
Australia is not without scammers either. Many years a go one certified farmer was supplying non grain from his relatives and selling it on as though it was from his property.
Australia has the unique opportunity as it is in the southern hemisphere and is closer to Asian markets than the South American countries where cheaper labour is an advantage. See chapter 25 Horticultural production for more market opportunities in specific fields.
Packaging
Larger enterprises can utilize the packing sheds and distribution centres of packing specialists and logistic specialists as well as marketing through brands. These may be more cost efficient for medium to large projects. We found by using our own carton designs and purchasing the 8,000 cartons needed at the beginning of the season along with the egg cartons and boxes we saved a lot of money and made a brand name for ourselves to sell.
What’s in a name you say. Everything. The brand name is great for instant recognition but means your quality has to remain high at all times. The name we applied to our duck eggs with the slogan gave us instant recognition. The recognition was strong or stronger than just the organic label attached.
“Daffy Drake Duck Eggs” – “The Duke of Duck Eggs” was known to everyone with the little black duck sitting on a nest in silhouette. In the organic industry and further afield in the Chinese communities this Label become synonymous at the time.
“AGMTOP” citrus – “Another Great Move To Organic Produce.” It also was the acronym to our names Andrew and Gail Mellis. These 2 labels were well recognised and made sales easier for everyone to recognise.
Organically acceptable or not?
The individual grower is responsible for the products used on his or her enterprise. The use of non acceptable inputs can result in suspension or loss of organic certification therefore it is necessary for the grower to keep abreast of any changes to organic certification of inputs the addition of deletion of certain products. If in doubt contact your certifying body. It is also important to note that some acceptable inputs like sulphur, lime and pyrethrum may contain prohibited additives. We found that pyrethrum we bought years before being certified was unacceptable because it contained pyrethrums with petroleum bi products. Fortunately we had not used the product as it was still unopened with the date on it.
Alternative pesticides could include such things as homemade insecticidal plant extracts or commercial products that are not registered by the APVMA as pesticides. The APVMA defines an agricultural chemical product as, “Any herbicide, insecticide and fungicide substance or organism used to:
* To destroy, stupefy, repel, inhibit the feeding of, or prevent pests on plants or other organisms,
* To destroy a plant or modify its physiology,
* To modify the effect of another agricultural chemical product,
* To attract a pest for the purpose of destroying it.
Organic fertilizers are not considered agricultural chemical products unless they have been modified in some way. Some naturally occurring fertilizers like crushed rock phosphate may contain cadmium which is a prohibited substance and as such should be first checked to see if it is acceptable or not.
Pesticides are considered organically acceptable if they are naturally occurring, have not been modified in some way and specifically target a pest ar group of pests and should be used to target the specific pest with minimal negative impacts on the environment. The pesticide should be free of additives. If in doubt contact your certifier first to check to see whether if it is acceptable or not.
An off label product is a product that is used for the control of one particular pest but the farmer may want to use it or trial it on another type of pest. Off label use of organic pesticides are acceptable provided they are:
* Organically acceptable by your certifying body,
* They are used in accordance with the maximum mixing rates stated on the label.
If the growers want to use off label products start with the lowest recommended rates first. We can testify to this with lime-sulphur water. With an outbreak of scale; in the first year of operation we wanted to test the products affectedness, on several Syzygium leuhmannii trees being grown for their fruits. We trialled the mix at the lowest rate and completely defoliated the trees within a few days. The 12, two year old trees never fully recovered yet lime-sulphur seems so harmless.
When trialling any substance it is a good idea to fully document what was done on the trial patch and compare it to other areas. Monitor the results. This is best done by measuring the end results, production rates etc. Use visible agents like photography for best results.
Notification of organic status to neighbours.
Neighbours should be informed that you are preparing for certification and again once certification has been granted and what is involved in the conversion process to organic certification. Try to ascertain some agreement on what they will do as good neighbours to minimize or eliminate any effects that their use of chemicals may have on your organic system. You never know they may join you in later years once they see the many benefits being derived from your farm. Following our certification many smaller farmers and retirees moved into organics though they did not seek certification due to the costs and small volumes produced. Two large pecan nut orchards also commenced operations and converted to organics so you see you may start the ball rolling
Below is an example of the type of communication used to notify
neighbours and others of the organic status of a property and to request cooperation in minimizing contamination risks.
This is necessary to help alleviate the possibilities of neighbours causing contamination and strengthens any possible legal action that may occur in the future. My neighbours at the time were the Coffs Harbour City Council and State Forestry. We also had a Power easement which the local Power Authority maintained. I was immediately informed that treatment of the power poles on my property would be treated differently however I would be expected to pay pro rata of any shortened life of the poles on my property which included labour for erecting same. This had to be accepted by me or I had no legal fall back if deregistration was created due to the power authority using hazardous chemicals on the poles as a preservative or had an accident. In fact the power authority requested permission to trial a new input which they considered would be acceptable to the certifying bodies. The results from the trial are still on going. As you can see most authorities will try to work in with you.
We had one experience where several trees were killed by the power authority (Their truck ran over a number of trees) The Authority paid the full compensation on the organic value of the trees and production of the trees without dispute so make sure the letters are sent out to all persons involved.
As previously mentioned else where we had on going battles with the Council over Noxious weeds until the weeds abated naturally on the property through better soil improvement and hand picking. The council did threaten to organize labour to remove the said noxious weeds instead of using chemicals. The local GREEN CORE had promised me assistance to remove the noxious weeds by hand if the council was ready to move in. Fortunately the council toned down its demands and allowed our experimental trials to continue as we were working on the problem. Long term everyone was a winner as the weeds succumbed as the pasture interrows improved.
I believe all the certifying bodies have a similar style letter that can be emailed to all the persons involved. Email is a good method as you can receive notification that the email has been received.
Neighbour or recipient’s Name Your Name
Neighbour or recipient’s Address Your Address
Phone Number
Email Details
Date
Re Organic certification
Dear ……………..,
I own the property at (location). The citrus orchard and vegetable crops located at location and am currently seeking certification/certified as an organic producer with certifier (name). This entails managing the property strictly in accordance with the certifier’s documented organic standards.
Because you manage the land adjoining my property on the north, south east or western boundary, I would like to inform you of my objectives and obligations as an organic grower. I strive to produce high quality fruit from a system which emphasizes the natural nutrient cycling without the use of toxic chemical pesticides, herbicides or fungicides to control pests, weeds and fungi. My enterprise relies upon biological pest control, and where necessary, a limited range of other naturally occurring inputs to manage specific nutritional, pest, disease, weed and fungi constraints. The organic standards strictly regulate the types of inputs permitted for use. The use of synthetic fertilizers, pesticides, herbicides and genetically-modified organisms (GMO’s) are not permitted by the certifiers.
Contamination of my orchard, citrus crops or vegetables with non permitted substances would result in the loss of organic certification of the crop and land for up to five years or in extreme cases indefinitely. That would translate into an economic loss due to the drop in premium prices presently being offered by the value adding of certified organic citrus and vegetables. As a certified organic producer/grower in conversion, I need to manage the risk of contamination of my property. I would like to request your assistance in minimizing any risk of accidental contamination of my property with substances not permitted under the organic standards. If you transport, store or use synthetic fertilizers, pesticides or herbicides on land adjoining my property, please take the precautions necessary to prevent accidental contamination of my property through spills, run off, spray drift, over spray or wind blown dust contaminants or any other toxic compound. Please notify me immediately if you believe such contamination may have occurred.
Thank you for your cooperation and we look forward to working harmoniously together for our mutual benefits. Please do not hesitate to contact me if you would like more information about my enterprise or certification.
Yours sincerely,
Name/signed
Retain a copy for your records.
Establish a New Farm or Convert an Existing Farm?
My isolation assisted greatly in reducing the risks to my organic orchard of chemical contamination and the introduction of pests, diseases and weeds from adjacent property enterprises as they were government owned identities mainly forestry and our own green belt which comprised over 85mm of the property. It also gave me the advantage of having a forest with existing predatory habitats at my finger tips.
Approaches to conversion
There are several approaches a farmer may undertake to convert part of his property to organics. The establishment of a new enterprise as versus converting an existing enterprise both have their own peculiar characteristics, both have their own integral complications or experiences as I like to call them. Hopefully I can point out many of the traps which confronted us and save the new, the experienced or converting farmer a few of the experiences that confronted us, making life easier and more viable.
Part Conversion
It is possible to have part of the farm certified while part of the farm remains in the conventional mould of using chemicals provided the crops and harvests are separated. The proprietor must be able to demonstrate that the methods applied through the growing, harvesting and packaging of both the certified and non certified crops remain in place and are adequately addressed so that the separate identities will remain intact through out all phases of the processes. One method is to grow different crops, or identifiable strains.
The proprietors must develop a program that shows the whole farm will comply and be converted within a 10 year cycle.
It is a well known fact that new orchards; from planting to the first harvest greatly influences the economic viability of an orchard in the long term. The growers and/or managers need to reduce the chances any setbacks during the establishment period during the early growth of the trees. This was a valuable and costly lesson we learnt in our first year in stage one of the orchard where 250 trees suffered sever frosts with bark split. The trees took years to recover and never matched the trees of the following two seasons. In the following 3 seasons the winters were milder, the sprinkler system was more adequate, mulches were deeper and of better quality, we cross ripped the fields to ensure better drainage and to break up the surface crusting and clay pan below and the soil itself was showing good signs of rehabilitation with good cover crops.
Immature orchards are also prone to suffer from moisture stress, nutrient deficiencies and insect attack as a result of their smaller root system which is less likely to supply all the trees need. Most organic orchardists establish new orchards organically using these methods:
* Reduce weeds by eliminating competition with a deep layer of mulch around the trees from the time of planting,
* Supplementing nutrition by adding high quality compost adjacent to the trees or adding commercial organic fertilizers in a semi liquid state. We later realized this could be done by soaking large quantities of chicken manure seaweed and fish emulsion together and watering it in. While it maybe rancid the ultimate result on young trees and as a soil conditioner is worth the trouble and smell.
* In the meantime high quality green manure pastures can be established between the tree rows using legumes and ryes or wheat or oats.
The location of the farm may influence its specific crops whether they be orchard trees, vegetables or nursery trees or ferns. Susceptibility to weeds, pathogens and pests will dictate the area used as will the physical constraints of the land like access and maneuverability of machinery.
Parallel production
Parallel production is similar to part conversion but relies on a single crop from a particular area on the farm. For example it may apply to lemons on a mixed citrus orchard, Granny Smith Apples on an apple orchard or rhubarb on a vegetable farm. Parallel production is a restricted practice and is closely monitored because of the increased risk of accidental or fraudulent mixing of products of different certification status.
General principles:
It is recommended that an organic farm establishes and or retains native vegetation on stations, along waterways, floodplains, watercourse riparian zones and wetlands. The provision of wind breaks and non cultivated buffer zones should be enhanced or left in a natural state.
Standards:
The enterprise is to include a minimum of 5mm of the land area to be returned to the environment to assist in predatory organism habitat and wild life corridors. Organic standards require this conversion to be done within 5 years of conversion. Some countries are looking at a minimum of 10mm.
Organic producers in fact all farming enterprises are in the best position to minimize environmental impacts, reverse environmental degradation and contribute to more sustainable landscapes. Good efficient layouts with management of farm biodiversity and landscapes is being recognized more. It is being progressively incorporated into organic standards. Hopefully one day soon the governments will see the importance of this role in not just as habitat control but also as carbon sequestering and assist farmers for the role they can play in sequestering carbon.
It may seem that there is no directly benefit to the enterprise however the accumulative affects are deemed worthy of protection as part of our natural heritage. The natural environment does contribute positively to the production system synergistically overall eliminating the reliance on toxic chemical inputs which include:
* Insect pest control
Beneficial control organisms benefit from the habitats provided and are ready to invade farm land as soon as an imbalance begins,
* Water filtration
Vegetation belts provide a natural filtration system purifying water for farmers down stream and slowing the water flow resulting in more water being retained on the block longer before it drains to the natural waterways preventing raised salinity levels and retains more water in the river systems after the initial floods have subsided,
* Environment & Erosion Control
The monocultural aspect of farming benefit greatly from the presence of biodiversity which in return is a valuable aid in the prevention of soil erosion and larger predatory organisms like amphibians birds, reptiles and marsupials by providing shelter.
To demonstrate the environmental responsibility of organic growers further in agriculture, revegetating non cropping areas even those unsuitable for agriculture is vital for:
* The prevention of weed incursions from the farm or tilled land to other sectors,
* They can be used as a natural barrier to exclude grazing stock,
* They assist in unavoidable spray drift from adjoining landholders,
* They assist in the uptake of excess nutrients which would normally leave the property allowing them to be recycled on the property.
Standards
The fertility and the biological activity of the soil must be maintained and increased wherever and when ever possible. Minimum cultivation of the soil should be initiated in an attempt to maximize the complex interactions between all the microorganisms and macro organisms. Only after this has eventuated will the biological fertility and physical textures of the soils increase; slowly at first followed by a more rapid rate. The better the physical and biological properties of the soil the better is:
* The weed management control either through cultivation or preferably grazing or mulching,
* The pest management using biological control applications,
* The disease management through biological controls the eventual breakdown of all fungicide residues in the soil,
* The soil structure remains intact without compaction by heavy machinery
* The nutritional cycle is maintained through green manure crops or organic fertilizers, supplements and manures,
* The efficiency of irrigated water through irrigating less often with less moisture variation, pH variation and temperature variation.
Because of its focus on reducing or eliminating chemical inputs and
improving soil health, organic management of soil alters many soil
parameters. As can be seen good soil fertility aids in the overwhelming benefits of fewer pests with less time and money spent on toxic pest control, less time and money spent on toxic weed management control and far fewer fungal problems.
Orchards in Spain that were analyzed by Albiach R, et al. (1999 – Structure of organic components and biological activity in citrus soils under organic and conventional management) and in Italy by Canali S, et al. (2002 – Soil fertility comparison among organic and conventional managed citrus orchards in Sicily Pages 235 to 242, concluded that the organically managed farmed soils were “found to be higher in organic matter, humic acid, carbohydrate, aggregate stability, microbial gums, microbial biomass and enzymatic activity” which are all strong indicators of soil metabolism with microbiological activity. All of these differences are of great benefit to the orchard, farm and pasture.
Humic Acid:
Humic acid is a collection of various complex acids that are derived from the partial or complete decomposition of dead organic matter. It is a complex mixture of different acids which are based on the carboxylate and phenolate groups so that the mixture reacts as a dibasic acid or at times as a tribasic acid in the soil. Humic acids can form complexes with ions that are commonly found in the environment creating humic colloids and fulvic acids. Fulvic acids are humic acids of lower molecular weight and higher oxygen content than the traditional humic acids. They are commonly used as a soil supplement in agriculture for buffering pH and forming chelates. The presence of carboxylates and phenolates enables the humic acids to perform complexes with ions like Mg2+, Ca2+, S (Usually as a metallic sulphate as a metal chelate), B2+, Zn(Usually as ZnCO3), Fe2+ and Fe3+. Many humic acids have two or more of these groups arranged so as to enable the formation of chelate complexes. The formation of humic acids in regulating bioavailability of metal ions.
Where the roots are is where the health begins?
Soil expands 150mm in 10 years
To change the soil significantly does take time, so organic producers need patience and persistence. The white highly leached clays; where we started the orchard, were compacted, infertile, acidic, yet contained a balanced level of most nutrients except the toxic levels of boron in patches and aluminum with a yellow clay base down around 350mm to 600mm below the surface. The top soil had been removed prior to purchasing. This was in reality the worst scenario for growing healthy crops. Copper and manganese were slightly below optimum levels. The interesting aspect though was despite most minerals being at optimum levels they were not available to the plants.
The citrus trees were in for a real shock coupled with the severe winter and drought that was to follow made the job far more difficult. Citrus are well known for their shallow roots and will grow masses of smaller feeder roots into the mulch layers on the soil surface if conditions are suitable. This rooting habit presented us with the ideal opportunity and challenges in relation to nutrient, water and weed management.
With 300 cubic meters of sawdust, 3 tonnes of pure organic blood and bone and about 50 cubic meters of grass clippings off the side of the road we had a base mulch which retained moisture but little else. We had little water as the dam had not yet filled and would not do so until late into the following autumn yet there was enough to keep the trees a live and green.
There was very little cover grass other than scattered clumps of parramatta grass, as the original ground was devoid of soil and with it grass seeds to get things moving. The ducks were having to roam over the whole orchard and onto the council land next door just to keep their bellies full.
Citrus also had a short stocky tap root and with the rye and Paspalum specie. We knew any nutrient deep down would surface through the slashed material that was not eaten by the ducks..
The lateral roots on a mature citrus can extend beyond the tree canopy but usually to the drip line which meant we had a lot of soil to improve.
This mid row area was covered in a fine layer of blood and bone, more sawdust mulch and lime. It was then planted with rye, wheat, Lucerne, oats, vetch and clover prior to an expected few days of rain. As previously stated this was a good exercise. We didn’t achieve the results we wanted but learned from experience that the white clover Haifa trifoliate with the rye grass responded best. Either that or the ducks initially found the other grasses better feed. It took another season before we acquired good results following better rains. It took another twom seasons before desirable levels of interrow mulch was seen.
As the time past all the varieties above except for the Haifa trifoliate became scarce in the orchard as the soil improved. The clover covered most the inter rows and grew an astonishing 200mm to 300mm every 2 to 3 weeks in consequent years. Galium sp. was one weed we had not expected but thrived under the orchard conditions and would grow a meter or more up the trees between slashing once the soil had reached an optimum level. The Galium offers good bulk that decomposed very quickly. Despite covering some of the lower branches we did not consider it a problem some weed so it was retained along with the clover.
We noted the depth of soil improvement from year 1 and it took some 4 years before things started to really improve. By the 10th year we had gained a few more experiences. The trees which were all grafted onto a 100mm to 150mm stock of Citrinus trifoliate were planted with the upper lateral roots at mulch level and with the 100mm to 150mm graft above the soil. Later trees were planted along the rip line with the lateral roots above the soil line where the soil was mounded to suit the trees final position mainly because of the mulch being laid at 70mm to 100mm in thickness. Measurements taken on the 10th year showed that most of the trees had the soil within 10mm to 20mm of the graft while a few of the grafts disappeared below the surface of the soil amongst the first trees planted. The non hilled interrow were now level with the hilled plantings.
The non compaction strategies with biological activity and composts had raised the soil level by 100mm to 160mm throughout the orchard, not withstanding that the trees may have also been raised a little during this time. Something we pondered and endeavoured to uncover without any success. This raising of the soil indicated that the soil had an extra capacity now to hold an additional 100mm to 160mm of rain water in air spaces and had far greater aeration once the water subsided. Worm casting were continually removed from around the tree trunks and scraped towards the drip lines. The soil was now a deep grey-black in colour with worm holes and colour penetrating to the clay subsoil which was now becoming indistinguishable without a clear demarcation layer.
Soil assessment
As can be seen from above the soil is a great starting point for detecting health and nutrition on the farm. It provided us with valuable information on the physical soil structure, how it changed over time and with chemical analysis was a record of health and productivity. This growth in height of the soil along with quality would not have been achieved if toxic chemicals and heavy machinery had been foisted upon the soils organisms over this period. Encouraging the biological processes, encouraged a balance of health which extended through the whole ecosystem including the trees fruit and those who consumed the fruits. This didn’t remain in the orchard as it flowed down to the dam and surrounding environment.
All this was achieved initially with large volumes of sawdust, blood and bone, road kills, road side grass slashings, grazing ducks, crusher dust from black basalt followed by a small side dressing of either sea weed or fish emulsion from time to time. Soil tests for soil assessments was carried out annually for the first 5 years but ceased as we began to reap the rewards and monitored the steady improvements of texture and fruit quality. Soil tests along with tissue analysis is a very important part of conversion until you are satisfied that everything is working well and is in proper balance.
Things that can be monitored easily with the eye; now the digital phone camera makes this observation relatively easy for future comparisons are:
* The percentage of the ground physically covered in living mulch,
* The root development of trees, vegetables or flowers,
* The soil structure including release from compaction and aeration,
* The water infiltration rate or holding capacity – initially a half an hours irrigation would see excess water pooling on the surface. After the 6th year irrigation had ceased but 12 hours of irrigating would see no water pooling anywhere on the surface,
* The activity of earthworms and other soil organisms after the first season was less than one per 200mm by 200mm down to the subsurface layer. The 10th year was a menagerie of organisms on the surface and subsurface while dozens of earthworms. (while this varied on the season we consistently found 16 to 26 worms in an area 200mm by 200mm and to a depth of 300mm to 600mm) The type of worms we found varied from 2 to 5 varieties with the largest growing to 400mm in length by around 16mm in diameter. Have you ever tried measuring the diameter of an earthworm it is damn well nearly impossible. These larger earthworms which may number 1 or 2 if you were lucky in a poorer area were not seen after the 4th year. I would assume without knowing more that the worms were displaced by competition, migrated away form the improved pastures to the Eucalyptus forests or preferred acid soils, to neutral soils, either way they were not to be found in the orchard.
The pH of the soil needs to be monitored until it stabilizers or reaches an optimum pH for the crop.
Soil biology
Soil biology or healthy soil is biologically alive. Biological living soils are always in a flux changing as the plants grow and die involving the interactions between beneficial organisms, decaying pests and pathogenic organisms. The plants overall health is tied to the microbiological masses of the organisms that exist in the soil. The flux includes the physical structure of the soil, the ebbs and flows of the nutrient cycles and the usage of the chemicals buffered by the humic acid within the soil which are in return affected by the uptake and return of all these aspects by the plants themselves and the moisture content of the soil. These on going activities play an important role in the suppression of many pests, diseases and fungicides within the soil.
Good organic management practices optimize the synergistic affects of all the soils organisms and chemical reactions. The University of Western Australia “Soil health”, the publications “Life in the soil” is available from the CSIRO at http://www.csiro.au/resources/pfrc.html and “Soil biology and Land Management” is available from http://www.docin.com/p-702376752.html
Soil organic matter
Soil organic matter is measured as soil organic carbon and includes all living and dead organisms in the soil, from microbes to plant roots. It is one of the most important components of soil fertility because of the major influence it has on the water and nutrient buffering along with increased nutrient holding capacity. The humic acid produced from the biological activity greatly increases the physical structure of soil at the same time. The living and dead organic matter are also food for soil organisms whose activities are responsible for vital life functions within the soil, including nutrient recycling, pest and disease suppression, structural development and decomposition of contaminants like pesticides which may take years, decades or even centuries in some instances.
Soil organic matter content of 2mm is considered the minimum requirement to be useful in holding water and nutrients in the soil. Levels can be increased by adding bulk mulches and compost and by growing cover crops on site as green manures, but it is typically a slow process that grows in momentum as the soil’s structure and mineral content improves until an optimum is reached.
After conversion to organic management, a Texas Citrus Orchard which used compost from feedlot cattle manure (20mm), corn meal and husks (20mm) and mixed leaves, wood chips and crop residues (60mm) was spread under the tree drip lines at 2.5 tonne to 5 tonne per hectare annually. After 17 years the soil organic matter level had increased from 0.3mm to 1.25mm. Rynk R (2002) Texas farm composts for organic production. BioCycle 43(1), Pages 31 to 33.
During trials in Australia’s Sunraysia district, medic cover crops added
about 3.4 tonne per hectare annually of dry matter to the soil and increased soil organic matter levels from 1.11mm to 1.47mm over four cropping seasons
In another Sunraysia example, organic matter levels in the soil of an organic citrus orchard were raised from 0.2mm to 2.3mm in 16 years by application of compost at the rate of about 8 tonne per hectare annually. Sanderson G, et al. (1999) Improving vineyard soil and water management using minimum tillage and drip irrigation. Final Report to Horticulture Australia Ltd. for project DAN 18
Assuming a typical moisture content of 50mm for composts, the three
examples above and others equate to an additional 0.02-0.03mm soil organic matter for each tonne of dry matter added annually. These values are only approximate but give some indication of what may be expected from bulk applications of organic material to the soil. Canali S, et al. (2004) Effect of long term addition of composts and poultry manure on soil quality of citrus orchards in Southern Italy. Biology and Fertility of Soils Pages 206 to 210. http://www.springerlink.com/content/etg688fd8cw3yqar/fulltext.pdf
So according to the Canali’s report our orchard had; some 45 tonnes of aged sawdust plus grass clippings, road kills, blood and bone and what ever animal manures I could scrounge at the time with returned yogurt added to the soil over the first few years. This would have increased the organic level in the orchard and vegetable flower seed production area by, over 4.1mm in the first few years plus what was growing between the trees and presented to us via the duck’s anatomy.
Mulch
Mulches are used frequently by organic producers to suppress weed growth, conserve soil moisture and protect the soil from temperature extremes. As seen above mulches add valuable organic material and humic acid to the soil as they decompose. The benefits of mulch can often be observed in a relatively short time and include increases in activity of earthworms and other organisms, water infiltration rate and soil moisture retention, and reduced soil compaction. These benefits, together with a moderation of soil temperatures and
increased organic matter levels, help create soil conditions that are more favourable for biological activity including tree root growth. This is especially useful in orchards especially citrus orchards which have many shallow feeder roots.
The story of mulching versus composting is a debatable subject. Most growers and certifiers claim that composting should be carried out for a number of reasons:
* Mulch is a great soil conditioner,
* It nutritionalizes the soils allowing valuable nutrients to become water soluble releasing them at approximately the same ratio as the plants need them,
* It releases natural pesticide, fungicides, herbicides, antibiotics and hormones into the soil,
* It kills many harmful pathogenic, pests while weed seeds are retarded or suppressed and more beneficial fungi are promoted,
* It promotes soil organisms at all stages.
Mulches compared to composting are:
* Better at erosion control because of their large volume,
* Take longer to decompose up to several months or a year compared to several weeks so can be used as long term feed stores for microorganisms on the farm,
* Better utilize and tie up soil nitrogen in the short term,
* Better at incorporating different bacteria and fungi to decompose the material often relying on macro organisms like worms and millipedes to assist that are based on the farm,
* Composts tend to add little extra to the soil with most the bacterial action occurring in the compost rows rather than the soil,
* Bulkier in handling,
* Some of the more volatile elements are lost to the atmosphere,
* The time taken to decompose may take longer than expected because moisture is inconsistent. This is especially true in new enterprises,
* A larger surface area is exposed to sunlight which reduce organism activity to the upper parts of the mulch but does create a sterile zone,
* There is a larger surface area exposed to the soil which increases most soil organism activity directly and indirectly with the soil.
The biggest disadvantage to mulching is the limitation of some input materials due to possible contamination from non acceptable indirect inputs like growth hormones and penicillin which must be composted to kill or neutralize them.
We personally preferred mulching as I believe it is more frequently encountered on every natural forest floor throughout the world where as composting is only encountered in isolated pockets like eddies where larger amounts of material may gather or where the activities of Megapodes like the Bush Turkey (Alectura lathami) build their communal nests.
Off farm mulches such as straw or Lucerne may be a source of additional weed seed so it is best to secure your supplies from a known source. Ensure the source of material is acceptable to you and does not contain known pathogens like Phytophora sp. All materials should be confirmed prior to being introduced to the farm as many pathogens will be difficult to eradicate after they are introduced. Our own experience can testify to this with the introduction of Kykua grass. It took for ever to keep it in check eventually we let it do its own thing, only smothering it in fresh hardwood mulch around the trees which restricted its vigor to some extent. The kykua rarely advanced into the inner rows where more competition between grasses and legumes were encountered but preferred the seclusion of the part shade beneath the trees.
Stable Humus and Animal Bedding:
* Is where woody material like sawdust or wood shavings are used. The material is higher in carbon and is coarse and large usually derived from the shrubs and trees, rather than soft material like annual weeds and perennial grasses. It is often soaked in urine so has a better Carbon:Nitrogen ratio than raw sawdust or wood shavings.
* These are usually better at forming strong associations with clay particles and heavier soils and as such are difficult to maintain with moisture in sandy soils,
* They decompose more rapidly when the soil is disturbed, cultivated, heated or subjected to frequent dry and wet cycles.
These points need to be considered as they contain higher percentages of carbon and may lead to some nitrogen deficiencies in the short term, are usually slower to break down unless well mixed with the animal manures. They are better spread over the surface, tilled slightly into the top layer of soil or mixed thoroughly and evenly if composted. This type of mulch works well with green manure cover crops which minimizes soil disturbance while the legumes enhance the nitrogen levels directly below the surface and the sawdust traps ammonium released from the soil which helps the C:N ratio and returns the ammonium to the soil as nitrogen as it breaks down.
We spread the raw mixed mulches following its initial aging (the sawdust we received was already 3 to 5 weeks old when it arrived) over the surface and sowed the green manure seeds into the mulch just prior to the weather bureau forecasting several days of rain. The seeds were presoaked to commence germination and the ducks were restricted to an area where the seeds were more densely sown or away from the area until the seedlings were established. Mulches were approximately 80mm to 100mm thick around the trees and 10mm to 20mm thick between the trees and the inter rows. Following the establishment of the inter rows with the grasses and legumes we spread the mulches over the inter rows immediately after slashing.
Surface cultivation
All the standards insist on minimal and shallow cultivation especially in orchards and plantations where cover crop sowing or weed management is being carried initiated. The idea is to minimize the mixing of the soil layers however as we found out from our observations where our top soil had been largely removed earlier. (our top soil) The sub soil and bottom clay layer were becoming intermingled without a distinguishable line between the two, 10 years after applying the first mulches.
This approach will help to preserve the structure of the soil profile. Different soil organisms tend to be distributed through the soil profile at different depths according to their requirements regarding temperature, moisture, light, pH, nutrients and oxygen. Deep cultivation that mixes soil layers will have a more disruptive effect on this soil life and so will reduce the benefits obtained from soil biological activity. As well as redistributing and destroying soil organisms, cultivation destroys the food source for some (plants), and their structures like worm and ant tunnels. It also disrupts the physical soil structure by destroying soil aggregates, and can reduce organic matter levels by speeding the mineralization of organic matter. Some of these negative impacts are greater when cultivation is carried out on soil that is excessively wet or dry.
Erosion control
Organic standards require soil erosion to be minimized with the preferred option of eliminating it or reducing it to normal natural levels of the surrounding bush land. Erosion control is best achieved using revegetation of local species with locally indigenous cover crops. Initial mulching, contour planting with good management of rainfall and drainage water practices being incorporated into the overall scheme in preference to irrigation.
Compaction & Deep Ripping
Since we sold our orchard we have revisited the property on several occasions falling into disbelief the structural damage taking place on the soil and trees. The ducks have disappeared, the soil now is being compacted with vehicles, ruts appearing along the inter rows and tracks to and from the orchard. The answer to one rut is to make a new track a new rut such is the thinking of many conventional farmers or city slickers.
This compaction leads to the reduction of good aeration and water penetration increasing the likelihood of disease with the inability of the trees to absorb restricted and declining nutrient levels of the soil with broken feeder roots exasperating the health of the trees. Yet our new home’s gardens are thriving. We attend there a few days a year following the establishment of the gardens back in 2007 and insist that the leases only use organic inputs. We carry out the fertilizing and maintenance of the plants on the few days we visit each year. The gardens have never been watered since the first few weeks of planting out and are established on deep coarse red sand at the top of the ridge. Palms have grown 6 meters while some of the rain forest trees have grown an astonishing 8 meters. What I say it is often better to do nothing than to interfere and do it wrong.
Soil compaction can be easily reduced by:
* The exclusion of heavy machinery as much as possible by using lightweight tractors and the grazing of fowls will ensure the soil is maintained in a healthy state,
* The Establishment of deep rooted cover crops like Lucerne and rye growth in combination with dense green manures like clover, millets and paspalum will ensure distribution of the weight over larger areas reducing compaction to the minimum,
* A permanent layer of mulch even sawdust acting like a rubber mat will absorb and redistribute the weight through the mulch rather than onto the soil,
* The process of deep ripping the soil with rippers is not new but it is the most sustainable method to kick start the process of aeration and water permeability long term.
When I started out on the first stage of the orchard we planted directly into the compacted subsoil believing that any disturbance was bad and that is what the certifiers required. WRONG – Our experiences later found that the best method was to spread the mulch then deep cross rip the field planting the trees on the intersections of the rip lines. Our reforested area and citrus trees to the west were on the worst area of the land to begin with produced the best results at the same time as those trees planted directly into the compacted soil 3 years earlier.
Today I am firmly of the belief that many of our inherited problems are attributed to the poor quality of our soils especially the compaction where air and water the life blood of the soil with its organisms are severely curtailed through compaction. Problems which can only be reversed with the implementation of a mixed program which directly and indirectly addresses the poor structure of the soil making it more conducive for the maximum biological soil activity that leads to a healthy 3 tier structure above the ground. Poor drainage coupled with high or low pH levels can be corrected quickly and efficiently with the inclusion of organic matter with the use of deep rippers.
Moisture
As previously mentioned deep ripping not only allows for better aeration but increases the quantity of water that penetrates into the soil. High levels of humic acid increases the absorption and buffering affect of moisture in the soil. Our orchard’s soils expanded by an incredible 120mm to 160mm over 10 years allowing for an additional 13mm to 17mm extra water penetration in times of good rainfall. This additional moisture is equivalent 130 liters to 170 liters of water per square meter or 1,300,000 to 1,700,000 liters a hectare. Thinking of it another way it is equivalent to an additional 15mm to 20mm of rainfall being retained on the property every time it rained and:
* It mitigates the potential for possible soil erosion in periods of heavy downpours,
* It vastly mitigates the reduction in nutrient costs due to nutrient migration off the property which is experienced by other farmers and thus reduces waterway pollution, algal blooms and the time of re fertilizing,
* It saves money by not having to reinvest in nutrient supplements following heavy rainfall or prolonged rainfall,
* It reduces the energy costs, labour and maintenance involved with irrigating crops,
* It decreases stress on trees and crops due to fluctuations in soil moisture levels,
* It promotes better use of soil moisture as the capillary action is activated from the lower inter tree row zones to the tree zones as the trees uses the moisture within its root zone,
* It decreases the soil temperature range especially in the upper zones where the most activity takes place,
* It increases and prolongs the maximum biological activities within the soil,
* It reduces the chances of increasing soil salinity levels which are critical to some crops,
* It reduces fluctuations in pH values.
* It decreases the sodicity of the soil decreasing the chances of toxicity in the acid metals and the likely hood of deficiencies in base metals,
Ground moisture retention benefits every living organism from the smallest to the largest while decreasing salinity, sodicity and maintaining pH at optimum levels.
Salinity – sodicity & pH
The salinity, sodicity and pH can have marked effects on biological
activity, physical structural, nutrient availability and other critical soil
characteristics. (For nutrient toxicities and deficiencies of specific elements see Compost and Elements for Growing.)
Excessive salinity, sodicity or acidity are commonly associated with prosodic soils in nature which are soils with poor to very poor cation and nutrient exchanges and are associated with soil degradation or soils that are easily influenced by human activity. They use to be classified as highly weathered or leached soils. Most Sodic soils are in fact created by human activity such as deforestation, over watering or over grazing giving rise to the situation of being highly weathered. Organic certifiers insist that salinity, sodicity and pH be corrected and maintained at a premium level.
Salinity as seen in previous chapters relates to the amount of dissolved salts, usually that of sodium chloride (common table salt), in the soil. Soil salinity usually results from rising saline groundwater tables and the application of salts in irrigation or rainwater. (See chapter on Saline tolerances) Practices that help reverse or reduce the risk of localized soil salinity include:
* The minimization of water applied to the soil reduces the amount of water being added to groundwater tables thus keeping the higher concentrations of salts at a lower level below the root zones,
* Optimum watering in marginal areas will help remove salt from the upper root levels to deeper areas in the soil,
* Reducing irrigation by deep ripping and the inclusion of humus,
* Use leaching methods to help reduce saline levels initially where possible then deep rip and add compost and mulches with green manures to maintain better quality water in the soil from available rainfall. In the meantime grow more resistant crops,
* Irrigate with low salt content water or rainwater will minimize the amount of salt being added to the soil on a regular basis,
* The use of subsurface drainage where necessary to remove excess water and salt from the soil upper regions.
Sodicityrefers to the amount of sodium; not salt, in the soil, measured as the percentage of the cation exchange capacity (CEC) that is occupied by sodium. The CEC is a measure of the soil’s capacity to hold the cations positively charged elements. These include sodium, calcium, magnesium and potassium by electrical attraction. Sodic soils contain more than six percent of the CEC is occupied by sodium and highly sodic soils contain more than 15 percent. Our soils were initially highly sodic and were in dire need of transformation with both Sodium and Boron being high and both being from the same origin, in that the soils were laid down as alluvial deposits in an ancient bay followed by uplifting.
Sodic soils; usually sodium chloride, develop to the point where sodium ions displaces the calcium held in clay particles. Sodic clay particles tend to disperse rather than stick together when they are wet without cover crops to protect them against erosion. This results in their instability causing them to collapse when wet and the setting hard often like concrete when dry.
The high annual application of gypsum is the recommended method for overcoming the problems of sodic soils. Where we had high aluminum causing low pH and acidity the initial application of lime was followed by the growing of beetroot and some silver beet to remove the boron and sodium from the property. The following 2 years we used gypsum as the acidity had been largely corrected.
Organic growers sourcing gypsum and phosphorous need to verify the levels of cadmium and other impurities as many contain unacceptable levels of these toxic additives. Organic certifiers set maximum allowable concentrations of cadmium and other contaminants in fertilizers and soil conditioners.
The pH which is a measure of Hydrogen ion concentration in a solution, refers to the strength of the acidity or alkalinity of the soil. It has a huge bearing on the availability of nutrient elements within the soil. The pH scale ranges from zero; extremely acidic to 14; extremely alkaline, with seven being neutral. Depending on the pH, some elements can be so strongly attached to soil particles and despite being present in high quantities are unavailable to plants, or are so freely available that they become toxic. This apparently is what happened with the boron in our soil. Most commercial crops prefer a pH of between 6 to 6.8 or 7.1 to 7.3. We started with a pH of 4.5 to 4.8 but never added anywhere near the recommended doses as laid out by the various agricultural departments. We used them as a top dressing and spread them in wet weather to prevent their dust being blown from the property.
High pH or alkaline soils can be reduced through legume crops like Clover or Lucerne, increasing the soil organic matter. Hardwood sawdust that has been partially or fully composted is especially good at neutralizing high pH soils.
As can be seen from the chart above our podsolic 4pH to 4.8pH soil should have received 10 tonnes of lime per hectare, in fact only 3 tonnes per hectare was used. What was considered acidifying hardwood sawdust was used extensively yet the pH corrected itself over the first couple of years.
Managing the Organic Nutrition for the trees, crops or livestock
Organic growers like to emit a philosophy of “Feed the soil, not the plant”. This philosophy reverberates continually through my book as the approach to healthy gardens and farms. The forests, plains and mountains have been doing it for millions of years successfully without human intervention. To return to nature is to again ape natures approach in healthy living. Nature recycles everything where as we humans do not recycle everything, concentrating the wastes to central collection points – dumps, tips refuge places for burial where the cycle is abruptly broken depriving the downstream organisms of vital food inputs to continue the recycling. With this break the nutrients are lost and the health of the whole system succumbs. Oh! What a waste. Nutrient cycling relies on the mineral nutrients from the base rocks added to water, air and with the catalyst sunlight creates organic matter which then decompose to form humic acid. From humble beginnings the rocks further decay with the disposed plant matter, manures and bodies of countless microbes, insects and other animals all collectively trapping or harnessing the this vital energy and sustenance for the next generation within the willful concentration called leaf litter or forest litter. The decomposition with this recycling of all these raw materials and organic material by other organisms including fungi, microbes, insects, worms and other animals gradually converts the complex nutrient elements they contain into simple element forms that the plant roots can again reabsorb and use for their own growth where they make more complex elements.
Nutrient management program
Draw up a calendar plan that collects information and what needs to be done when especially in relation to nutrient and pest management.
The most economically and environmentally sustainable yield may not be the maximum possible yield when input costs are compared to output returns. The growth rate of a tree may be dependant upon the availability of nitrogen which is supplied by various Rhizobium species. These bacteria extract the protein building block nitrogen from the atmosphere so as a result work best in soils where adequate soil aeration and moisture are available. The Bacteria form nodules on the roots of leguminous plants like Caesalpiniaceae, Fabaceae and Casuarinaceae species and under other than optimum growth will discard roots or the bacteria which another species recycles. Under favourable conditions which are more likely to be met in a balanced system the plants are able to produce better yields over longer periods.
Interesting to note that field experiments conducted by the SANIIRA Institute in Tashkent in Uzbekistan showed that the production of fruit in bean species trialled actually increased when the plants were subjected to water stress compared to those plants grown where conditions were close to perfect.
In Humans most rushes in weight gain occur immediately after the body is placed under stress. Little weight is lost if the body is not under stress.
As an athlete I decided to placed my body under extreme stress with a harsh rigorous training for a week. I took my normal diet and added 10mm more of each food I normally ate The result was despite the increase in food in my diet I still lost 4.1 kilograms. The body’s muscles and tissues are actually under stress and will discard body mass or weight quickly. As soon as the rigors of the exercise program ceased and returned to normal despite the food regime being decreased by 10mm of what I normally ate the body recouped most of the lost weight; 3.7 kilograms, by the end of the week. This indicates that the body used the resources far more efficiently when the body was not under stress but followed immediately after the stress period.
These 2 experiments indicate that some stress is in fact good for the biological system to function at their optimum ability and that system can regulate and or tolerate fluctuations of stress.
Acceptable inputs
Most natural occurring living or once living organisms can be used as mulch or in composts. This has been covered in detail in the chapter on “Composts and elements for Growing.”
They include:
* Most animal manures including human waste provided it has been well composted as human waste often carries contaminants, hormones and drugs,
* Most animal by products such as fish meal, feathers, milk products like yogurt and blood and bone provided they have not been treated, plant waste that is not treated are acceptable organic inputs,
* Organisms like earth worms and their by products like worm castings or worm liquid provided no additives have been added,
* Biological preparations, including microbial and botanical provided they have not been treated in any way,
* Plant by products such as sawdust, wood wastes, wood ash and straw provided they have not been treated in any way which includes copper-chrome-arsenic,
* Seaweed and algal and their respective preparations provided no additives have been added,
* All bio dynamic preparations,
* Mined carbon based materials like coal humates or humic acid provided no additives have been added and they are low in contaminants and heavy metals,
* Minerals from natural sources including gypsum, lime, clays, rock phosphate, rock potash, epsom salts, zeolites or crusher dust. Organic growers need to first ensure that the products do not contain fertilizer additives or banned substances like cadmium.
* Trace elements must adhere to the biological codes meaning that basically only natural chelating agents are permitted. Perlite (pumice) and vermiculite (mica) are allowable as potting mixture ingredients along with composts,
* Fly ash is an organic substance that I presume would be an acceptable organic input; provided it is free from heavy metals, however it would be best to talk to your certifier for better clarification on the substance. Many coal burners may not be acceptable because of their production of high levels of carbon dioxide emissions. Understanding this modern coal burner power stations are being designed to remove the carbon dioxide before it reaches the atmosphere and bury it as carbon in special underground tombs. Whether this would be accepted is unknown to the author and may rely on chemical analysis on whether the fly ash contains acceptable levels of heavy metals. This may vary considerably on the source of the coal being used and over time. See the results of various power Stations around the world. This constituted a part of our potting mixes in the early days in the nursery with the major part being burnt coking coal.
India produces 170 million tonnes of fly ash annually while Europe produces 40 million tonnes. China Russia then America are the largest producers of fly ash.
Tests on fly ash by Snigdhasushil & Vidya Batra from 3 major power plants in India indicate that the following heavy metals were present in their coal burning fly ash Chrome (Cr), manganese (mn), Lead (Pb), Zinc (Zn), Copper (Cu), Nickel (Ni) & Cobolt (Co).
The Indian Power station analysis indicated that India was on the lower end of all trace elements compared to the U.S.A, Europe and Chinese coal supplies but were significantly higher than Australian Power Stations. Australian Power Stations were generally much lower with a complete lack of Chrome. (Note the scale level differences used in the final results.)
Experiments using Fly Ash as a field soil supplement; by Joseph L Frail jr., at an equivalent of 70 metric tonnes per hectare produced between 5 times to 30 times the biomass than plots without any fly ash. There were no toxic effects were observed in the 2 grass species grown.
Potted plants grown by us in the mid to late 1970’s in the nursery using coking coal as coarse material and fly ash as the fines with Australian native plants came from the Bulimba Power Station. The results compared to a standard potting mix were very mixed depending on the plants grown at the time. Most Grevillea species were slow to respond where as all the Myrtaceae species grown were relatively robust and had magnificent colour in the foliage compared to plants grown without the fly ash. In fact the quickest growth with strong root development was observed with Eucalyptus grandis. Liliaceae species and Laxmanniaceae species had relatively good colour but developed very large thick rooting systems making them great landscaping subjects but had poor holding and display properties in the nursery meaning that they needed to be potted into larger pots more frequently. This was also problematic when transplanting as the roots were often protruding from the pots or had grown outside the pots meaning they had to be trimmed prior to planting. Most of the commonly grown ferns displayed good colour with moderate growth as did the palms though some species developed poor rooting vigour. Cyathea cooperii had good colour, good form and dense tightly packed fronds in the crown. Generally the results were superior to those of the standard mix though flowering was not undertaken in the trials.
The pH of the fly ash was consistent at 5pH which should not have been a concern for the Grevillea species. The pH values vary widely in Australia from 3.3pH from Muja in Western Australia to 9pH from Gladstone in Queensland. This alone would be a very strong determining factor if fly ash was considered a viable alternative trace element supply, fill or potting mix bulk additive.
According to S M Pathan; L A G Aylmore; T D Colmer file number 12708694 the water holding capacity of fly ash in field trials was three times higher than the surrounding land. The hydraulic conductivities in the fly ashes tested were 105 to 248 fold slower than in the surrounding soils meaning that fly ash could be a very suitable, cheap weed free additive to sandy porous soils. They also found that fly ash cation exchange reacted vastly different depending on the source. This adds weight to what we found in the nursery with the mixed results on the different species. Any use of fly ash should be tested in small plots. If the results proved unsatisfactory the plots could be diluted down easily with the surrounding soils.
* Compost teas and any organically based liquid preparations made from any of the above ingredients or mixtures of the above ingredients are acceptable including fish emulsion and sea weed extracts.
The bio dynamic preparations and the compost teas are soil activators rather than actual nutrient inputs. Their purpose is to enhance and stimulate microbiological activity by inoculating the soil with a range of microbes.
It is essential to vary the types of inputs with a broad and variable range of elements which include both on farm compost and purchased natural biological products or raw mineralized products. To continually use the one form of inputs for nutrients more than likely will result in nutrient excesses or deficiencies in the long term. The same response and ailments would be seen in humans if our diets were stagnated to just one or two food items. A wide variety of inputs also results in a wide variety of micro organisms and macro organisms.
High chemical diets cause many problems in humans and animal studies from mild allergies and asthmas to cancer in humans and narrow based chemical diets cause many problems in plants like soft growth, pest susceptible foliage to flower drop.
On our farm we used everything that was available to us in order to mitigate any such problems and to give our crops the best range of inputs to maintain the health of all our plants. We used everything that was available in the local district which included hardwood Sawdust, road side grass slashing, Organic Blood and Bone, out date Yogurt, crusher dust from a local black basalt quarry, road kills, house hold waste, rock mineral, pig manure, stable manure, sea weed when available, fish emulsion, vegetable scraps from a local green grocer and even hair when that was available. Even power line refuse was used when the workers were in the district cleaning the easements.
Organic farmers need to better understand the reactions and interactions better than chemical farmers as the subtle differences appear and evolve differently throughout the year and through out the life of trees in orchards and plantations. These subtle differences may affect the crops significantly in the early stages of development and trees in the juvenile stage and may take weeks or even years to overcome. They may appear in the leaves, buds, fruits stems, or soil giving signs that something is in transition or at the worst wrong. Most problems that are subtle are soil related problems.
Soil & Plant Analysis
Organic certifiers require annual soil and leaf tissue analyses because of their value in monitoring long term trends in such parameters as soil fertility mineral content, pH and organic humus levels and nutritional uptake of the plants. here if the plants have low magnesium yet there is high magnesium in the soil the farmer wants to know why.
Annual monitoring also gives us trends to what is happening. These trends can be plotted to give the farmer an indication of the long term sustainability of the farm along with what actions can be taken to mitigate future issues which may arise so appropriate action can be taken. Soil properties are usually slow to develop and proceed with trends taking years to be displayed therefore soil analyses are usually recommended to be performed every three years however annual analyses will provide the organic farmer with a more accurate and detailed report. Initial changes in things like liming or chelating may show trends earlier than humic trends and natural changes like those created by worm castings and other microorganisms.
Leaf analyses is the best tool for monitoring the nutrient status of the crops and are akin to blood testing in animals. Small changes in soil activity may be exasperated several fold in plant tissues. Leaf analyses is a useful tool to confirm or dispel visual symptoms of a nutrient excess or deficiency. Many organic growers use annual leaf analysis coupled with soil analysis to better coordinate their management strategies in order to maximize resource use efficiency and improve the quality of their crops being grown.
Boron problem was cited after specific leaf tissue samples were taken. As the soil samples were taken over the whole orchard the boron in the soil indicated levels within the normal range. It wasn’t until the citrus in one part of the orchard displayed typical boron problems or should I say the leaves with stunted growth, yellowing and brown burns displayed typical salt level burns. The agricultural Department decided to do a leaf tissue analyses to confirm salt however the strategies quickly changed when we were told the problem. The history of the rocks would also back this up with the soils being alluvial deposits in an old bay. Where the trees planted the sub soil was deeper which may mean the area was in a slight depression and with uplifting and evaporation the boron which is less likely to be leached was accumulating in that area. History lesson over now what strategies were needed to overcome the problem.
High water use was the first strategy to try to leach the boron out and to move it down stream. That would work as the slope was away from the other trees. Problem leaching would also leach other vital nutrients out of the soil like calcium and nitrogen.
Keep the moisture level of the soil high enough so that the trees may grow out of the problem. Problem what if the trees don’t grow enough to overcome the problem or the roots spread further and take up more boron?
Have the ducks consume the grass and legumes and hopefully that would spread the boron over the rest of the orchard. Problem that may spread the boron further afield causing more problems down the track.
Now for something innovative. Why not grow an annual crop that would remove the boron and make money at the same time. Beetroot. Beetroot requires higher levels of boron in the soil and would take up the excess quickly. It would give us an interim winter crop with returns while the leafy summer crops could be marketed as a new succulent leaf vegetable at the markets similar to silver beet. Everything went well in the winter however the summer crop fell fowl of marauding grass hoppers, katydids and everything else in town so we let the ducks back into this section over the summer period. Well I suppose the grass hoppers and katydids enjoyed themselves and many moved on taking my toxic cargo with them. Three years down the track and their was little evidence of the Boron in the soil yet the soil test remained the same while the tissue analyses still showed levels on the high side of acceptable. As the trees grew larger the boron became less of a problem.
Analytical services
There are numerous soil and plant tissue analysis services available through state agriculture departments and agricultural suppliers. Developing a long term relationship with one provider is far more beneficial to the farmer and provider. The farm history is all in the one place with back up records should something go wrong. Comparable analyses from a single laboratory, using the same sampling procedure and equipment will give more consistent results over time with the biochemist or agro chemist already knowing what strategies are in place.
Theophrastus (370 – c. 285 B.C) noted the importance of climate soil types and soil health to the health of plants and the consequential relationship of health in humans.
A science that is today in its renaissance through the organic movement and particularly the work of William Albrecht (1888 – 1974) who saw a direct link between soil quality, food quality and human health. He drew direct connections between poor quality forage crops and the ill health in livestock.
Albrecht was outspoken on matters of declining soil fertility, having identified that it was due to a lack of organic material, major elements, and trace minerals, and was thus responsible for poor crops and in turn for pathological conditions in animals fed deficient foods from such soils.
His paper on Plant, Animal and Human Health Vary With Soil Fertility studied many clans and concluded that poor soil health led to poor quality food which leads to general loss of mental acuity in the population, leading to degenerative metabolic disease and early death.
Albrecht also researched the importance of calcium and of the balance between some of the major soil elements in relationship to a plants ability to take up or the inability to take certain elements from the soil. The inability of a plant to take up certain minerals leaves the plant stressed or malnutritioned. He did this unaware of cation properties of minerals in the soil and how they directly affect the plants ability to mobilize elements in the soil.
Nitrogen mineralization & availability
While maintaining adequate soil and crop levels of nitrogen is more
challenging for organic farmers and managers. Initially much of the nitrogen on organic farms becomes unavailable to plants due to it being tightly “bound up” in complex organic compounds such as micro and macro organism proteins. Nitrogen along with many other nutrient elements only become available to plants as the organic material dies and begins to decompose and once again enters a water soluble form.
Of all the inputs especially for orchardists and plantations nitrogen is the easiest nutrient to supply and it is basically a free input. It is estimated that a little over 1.2 kilogram of nitrogen per tonne exits in mandarins. Other fruits may vary but is usually less than 2.5 kilograms per tonne. Our orchard produced between 85 tonnes to 100 tonnes of fruit when in full production on an annual basis. This means that90 to 110 kilograms of pure Nitrogen is required to replace what the fruit removes from the orchard of half this amount per hectare. This would vary on different trees in different locations bought about by temperature, other chemicals within the soil and the type of crops being grown. As an indicator we could say on growing trees in their peak of condition may require a further 2 to 150 kilograms of pure nitrogen is required to maintain healthy growth per hectare per year which is tied up in foliage, branches and twigs. In total a healthy citrus orchard requires about 42 to 210 kilograms of pure Nitrogen a year to maintain full healthy production. Added to this there is an unknown quantity of nitrogen needed to sustain the healthy growth of legumes and green manures in the inter rows and duck feed.
Assuming and we should never assume that the grasses and legumes require a similar quantity of nitrogen until a balance is reached. A field study carried out over 2 years by Rocky Lemus, David J. Parrish & Ozzie Abaye with Panicum virgatum removed 100 kilograms of pure nitrogen per hectare per year. Two harvests were carried out annually during the trials. It was further noted that nitrogen inputs amounted to zero kilograms, 90 kilograms, 180 kilograms & 270 kilograms per hectare with no significant differences in the total nitrogen biomass being removed from each of the plots.
Ledgard & Steele 1992 and Whitehead 1995 found in field trials in New Zealand where white Clover Trifolium repens was the dominant species and fixed 100 kilograms to 350 kilograms of pure nitrogen per hectare per year and up to 650 kilograms where it was the major pasture cover. Where C02 levels were higher in the atmosphere like around industrial centers the rate of nitrogen fixation was actually much lower. Controlled greenhouse plants indicated that CO2 directly caused the suppression of 72mm to 89mm of the nitrogen produced despite the rhizome activity being identical.
Looking at the presumed average extracted from these figures it is reliable to believe that 220 kilograms to 450 kilograms of pure nitrogen is fixed and released into the soil in an average season per hectare where periodic slashing is carried out. While this may seem on the surface to be a negative result for the trees in an orchard it must be remembered that we are not removing all the nitrogen off site. Only a small proportion is removed by the seeds in cereal crops with the remainder being recycled and an even lower proportion is being removed by the citrus fruits going to market thus giving an overall net increase in the available nitrogen available for healthy plants.
Further when Trifolium repens is used as a cover crop it releases more than 3mm N into the soil as soluble nitrate which peaks at around three weeks following slashing and five weeks after incorporation into the soil. The overall release of nitrogen from the roots of the cultivated crop far exceeds that of the slashed portions. As citrus trees flushed 3 times a year we deliberately slashed our inter rows two to 3 weeks before the flushes commenced or at the time the apical buds had commenced swelling. This ensures the maximum amount of Nitrogen was available at the time the trees were in active growth and their nitrogen demand was highest.
It is not until all the processes are in place and a balance, a chaotic balance is achieved that “mineralization” can occur. Mineralization is when the soil organisms have reached their optimum balance of life and death where organic compounds complete decomposition and conversion of the proteins form simple, soluble nitrogenous forms that are readily absorbed by the plants to again make complex proteins.
Importance of the carbon: nitrogen ratio
Given suitable temperature and moisture conditions, the rate at which nitrogen becomes available from organic material depends largely on the ratio of carbon to nitrogen (the “C:N ratio”) in the material (This has been explained at length in the segment Composts & Elements for Growing).
The importance of the C:N ratio cannot be underestimated when it comes to supply and demand. For microbes to function and reproduce, they need an energy source. In the soil this energy source is the carbon rich sugar compounds in dead plant material. Energy to drive the process is supplied from carbon and nitrogen proteins with other trace elements involved or not involved in the direct reactions. Carbon dioxide is released in the reactions. Most soil bacteria have a C:N ratio of 6:1, and so to grow, these bacteria must be able to access and consume more than double the carbon they need to maintain the 6:1 C:N ratio. Organic matter with a C:N ratio greater than 30:1 is grossly inefficient being deficient in nitrogen for soil microbes to adequately access the energy in the carbon rich compounds. The shortfall in nitrogen means organisms need to extract mineral nitrogen in the form of nitrates and nitrites from the soil. This causes “nitrogen draw down” depriving the crops and plants with the nitrogen they need to build new proteins in the short term until the microbes themselves die and decompose.
Organic material with a relatively high carbon to nitrogen ratio (C:N less than 20:1) contains all the nitrogen necessary to allow an explosion of activity in decomposition by microbes which results in nitrogen being released into the soil early. The soil moisture content and soil temperature, different organic materials can exhibit very different rates of nitrogen decomposition and nitrogen release. Several experiments world wide have shown that the lower the carbon in the C:N ratio and the higher the percentage of nitrogen within a material the more rapid is the release of soluble nitrogen to the plants
The soils ability to take up Nitrogen is affected by several external factors which include:
* Moisture content inhibits the soil’s performance when it is either very wet or very dry conditions,
* pH restricts or inhibits the soil’s performance when it is either below pH5 or above pH8,
* The temperature generally increases the soil’s performance as the soil’s temperature increases,
* C:N ratio draw down of soil nitrogen decreases proportionally as the soil C:N rises above 11:1,
* N isreleased to the soil proportionally as the soil’s C:N falls below 9:1,
* Cultivation or other disturbance decreases mineralization increasing N losses to the atmosphere.
Nutrient cycling
Organic certifiers promote the recycling of nutrients on a farm as the basic fundamental aspect of organic farming. Nutrient cycling can be achieved by the returning of as much farm “waste” as possible to the farm. The use of green manure and cover crops with the inclusion of livestock wherever practical is highly preferred.
Recycling of citrus tree nutrients
According to Dou H, Alva AK, Khakural BR (1997) pages 1226 to 1232 of the Soil Science Society of America Journal a significant proportion of the nitrogen and other nutrient elements in older leaves are redistributed within citrus trees before leaf drop occurs. However the nutrients in fallen leaves and dead roots still account for up to 153kg of Nitrogen per hectare per year on mature orange trees and up to 84kg per hectare per year on oranges trees that are 4 to 7 years of age.
Pulverized citrus tree leaves were incorporated into a sandy soil and nitrogen mineralization became available within days. Ammonium nitrogen levels peaked after 20 days with 60mm of all nitrogen in the leaves being mineralized after nine months according to Dou H, Alva AK, (1998) pages 13 to 24 of Journal of Plant Nutrition. While the rate of nitrogen mineralization is likely to be less under the drier conditions prevailing in most of Australia’s citrus districts compared to Florida, the cycling of nitrogen from mineralized tree residues should be taken into account when developing nutrient budgets.
Therefore tree pruning’s should be dropped where they are cut for mulch and stubble or plant residues should be returned to the farm for complete decomposition and mineralization.
Cover crops & green manures
Cover crops and green manure crops are the “Living Weeds” or chemical factories on the farm. They are specifically arranged with specific plant species to distribute specific chemicals along with bulk sugars, bulk proteins and humic acid to benefit the soil its microbe organisms and as a consequent benefit the other desirable plants being grown.
Annuals and perennials are used for different purposes and are usually left to regenerate naturally by self seeding or can be collected and broadcast the following season. Bulk and deep rooted plants are best achieved with perennial grasses while green manure legumes can be used as annuals or biennials. To help control certain fungi, nematodes and deter pests many of the Asteraceae like stinking Roger, Tagetes minuta or the Marigold, Tagetes patula make very good plants with medium bulk to high levels of bulk. We grew Tagetes minuta because of its large size and bulk. It is a little problemsome when it germinates close to the trunks of the citrus trees but apart from that it gave excellent results. It is also a good duck repellant as the ducks will not sit under trees where the plants are nearby.
A general introduction to the use and benefits of green manures applicable to a large range of crop systems can be acquired from the Primary Industries Victorian Report Note “Organic farming” Madge DG, Jaeger C (2003). The grower’s choice is determined largely by their crop requirements in relation to:
* The need for nitrogen balance is made by growing legumes for nitrogen input in poor soils versus grass legume mix in fertile soils or a mixture,
* The need for greater bulk in the organic soil – cereals and grasses generally produce more dry matter than legumes,
* The need to reduce pests by attracting predatory organisms is best attained by growing a mixture of grasses that this some that deter light brown apple moth for example. The pollen of many grasses feed predatory mites or their larva. The nectar of certain flowering grasses is also food for beneficial insects)
* The need to reduce pests through chemical control or undesirable oil scents can be achieved by growing Tagetes species,
* The growth habits of many plants need to be prostrate or semi prostrate species as they are less likely to interfere with micro jets or persons carrying our their tasks. Trifolium repens is an excellent all round plant on the north coast of New South Wales,
* The active season winter/summer can deploy seasonal dormant species.
List of the advantages of cover crops in the orchard
Cover crops and green manures have many benefits to the farmer that include:
* Assisting greatly in soil erosion in riparian zones as well as through orchards, plantations, stubble left in cereal crops or vegetable and flower beds,
* Providing forage for fowls or sheep through the farm, may be used for groundcover management and extra income,
* Providing a reliable food resource for predatory organisms especially arthropods when feed is scarce or during certain life cycle stages,
* Protecting the soil’s moisture content and drawing water during very wet periods and by reducing evaporative losses during dry periods,
* Improving water infiltration which benefits plant growth slows runoff and prevents soil from crusting,
* Building soil aggregates so that roots can maintain reliable exudates to absorb dissolved nutrients,
* Strengthening and multiplying the number of fibrous roots which in return binds the soil particles together,
* Capturing deep water and nutrients deeper in the soil often recycling leached nutrients beyond the target crops root zone,
* Breaking up hardpans while preventing caking of top soils and disrupt distinctive soil layers. Lucerne is ideal for this type of work,
* Enhancing habitats for both soil organisms and predatory organisms by creating plant diversity,
* Cover crops are essentially controllable weeds that control problemsome weeds while enriching the soil for all soil organisms and above ground predators,
* Providing habitat and protection for beneficial species including predators and parasites which are beneficial, maintaining predator diversity,
* Adding valuable organic matter to the soil, the surface litter while the roots continually extract and add organic matter to the sub soil,
* Fixing atmospheric nitrogen through symbiotic relationships with bacteria mainly on the roots of legume root nodules,
* Storing nutrients both in dead and live plants preventing nutrients leaching from the soil,
* Regulating soil temperatures causing less stress,
* Preventing strong air currents removing fine particles and moisture from the soil surface,
* Harbouring of higher order birds and reptiles which add to the diversity of the predators within the orchard.
List the disadvantages of cover crops in the orchard
While there are many advantages there are also a few disadvantages to growing cover crops and green manures that include:
* The soil water requirements will be greater,
* They require soil nutrients depleting some minerals until a chaotic balance is gained and an equilibrium returns,
* They can harbour unwanted noxious weed seeds that may germinate years later,
* Under unfavourable situations can harbour unwanted pests,
* They have been known to harbour rodents and snakes which have both beneficial and frightening experiences for some workers.
How to determine the nitrogen content of a cover crop
or a green manure
To calculate the approximate nitrogen content of a cover or green manure crop requires a laboratory analysis of the percentage dry matter and percentage nitrogen of a sample of the crop at the time of harvest, and a simple calculation. To do this harvest the complete plant roots, stems and leaves from an area totaling one square metre of the crop. This can be done in several small patches. Use a pattern formation as you would do for soil samples and leaf tissue analysis and take average looking samples. Weigh the freshly harvested sample to get the FRESH WEIGHT in kilograms per square metre. Ensure all soil has been removed and the samples are free of surface moisture.
Send a sub sample of whole plants to a soil or plant analytical laboratory for analysis of DRY WEIGHT mm of the fresh weight and DRY WEIGHT NITROGEN mm how much of the dry weight is nitrogen. The laboratory will advise on how much to send and how to package the samples. Calculate the kg of nitrogen per hectare = FRESH WEIGHT x DRY WEIGHT mm x DRY WEIGHT NITROGEN mm Example: A FRESH WEIGHT of 7kg is harvested from one square metre. The laboratory analysis shows a DRY WEIGHT mm of 14mm and a DRY WEIGHT NITROGEN mm of 4.3mm. The crop’s nitrogen content is 7 x 14 x 4.3 which equates to 421.4 kg of nitrogen per hectare of cover crop.
If the green manure crop covers a proportion of the orchard or plantation like only down the inter rows, then the crop nitrogen content can be adjusted accordingly. To determine the nitrogen content per hectare of orchard.
In our orchards we had about 60mm green manure crop cover with the remainder comprising of Rye, Panicum, Galium and Paspalum species. Now calculate the mm of coverage by the amount of Nitrogen 421.4kg of nitrogen by .6 per hectare of orchard. Our orchard was producing a total of nitrogen of around 253 kilograms of pure nitrogen per hectare.
We usually slashed when the crop was about 400mm in height and slashed it down to about 100mm in height. To calculate the approximate release in nitrogen available now multiply the kilograms of nitrogen per hectare by the mm of the crop slashed. Our orchard was releasing more than 190 kilograms of pure nitrogen per hectare every time we slashed plus what was tied up in the other grasses at the time.
Cover crop or green manure?
This choice depends on the priorities and objectives of the farmer and the crops being managed. For soil improvement prior to orchard establishment, a well grown green manure will boost short term soil organic matter, nitrogen and overall nutrient levels more rapidly than a cover crop and more cost effective than applying compost or other soil additives.
Compost
Compost is the single most important additive that nature can supply for growing healthy plants.
* Good composts will have good moisture retentive qualities when added to the soil,
* Good compost creates good aeration when added to the soil,
* Good compost will have a balance of minerals and nutrients,
* Good compost will have a good buffering affect on the soil,
* Good compost will have a pH measurement of 6.7ph to 7.1pH and will aid the take up of nutrients in the soil.
* Good clover will produce 50 to 200 kilogrammes of Nitrogen a year per hectare which is considerably more than what is required by most mature fruit bearing trees.
The pH will vary on what organic materials you use in the blending to make the compost.
The stocking rates for commercial free range egg production chickens is a maximum of 1500 chickens per hectare for conventional management practices and 1000 for organic management practices.
The figures in Table below are provided only as a guide and are based on birds that are supplied with all their feed requirements thus the table does not take into account the elements removed from egg production. Kaki Campbell ducks can lay an egg a day under ideal conditions where the birds are not stressed.
Note above the amount of Nitrogen produced with healthy clover was between 100 and 600 kilograms per hectare per year.
It must also be pointed out that the poultry would gain nitrogen from consuming the legumes at the same time.
Quantities Removed through Fruit from:
Falivene S (2005) ‘Orange crop mineral nutrient accumulation and removals charts.’ (NSW Department of Primary Industries: Dareton, NSW.). http://www.
australiancitrusgrowers.com.au/PDFs/resources/Orange_Crop_Mineral_Nutrient_Accumulation_and_Removal_Charts.pdf
Total Inputs from:
Moulds G, Tugwell B – 1999 ‘Citrus growing manual: a manual for quality decision making’ (Horticultural Research & Development Corporation)
Egg laying information from:
Western Australian Broiler Growers Association, Poultry Farmers Association of Western Australia (2004) ‘Environmental code of practice for the poultry industries in Western Australia’ Perth Western Australia.
Growers also need to distinguish between nutrient imports into the
orchard and nutrient cycling within the orchard. The amount of nutrient that is a ‘new’ import will depend on the ratio in the diet of on site forage to purchased feed (such as pellets and wheat). There two points to note from the table are:
* Relatively low poultry stocking rates can make a significant
contribution to citrus mineral nutrient needs, (We stocked at 200 ducks per hectare.)
* Depending on the balance of elements in commercial feed the manures can contain levels of micronutrients like iron, zinc and manganese far in excess of what citrus requires.
It should be noted that some organic standards and quality assurance
schemes in other countries restrict the application of raw animal manures to food crops for specified periods prior to harvest, where there may be a risk of microbial contamination of the crop. In the U.S.A there maybe a withholding period of 90 days for crops not in direct contact with the soil. Growers of export crops should notate these requirements and have the animals agistted elsewhere on the property for the recommended withholding periods. These restrictions may also be interpreted as applying to direct deposition of manure by livestock, which may need to be managed accordingly.
Mycorrhizae are Different to Nitrogen Fixing Bacteria
Mycorrhizae is Greek-Latin for “fungus roots.”
Whereas Nitrogen Fixing is carried out by Bacteria which form nodules on the roots of certain plants and work within the confines of the nodules Mycorrhizae penetrate the root cells of the plants they form symbiotic relationship with. They literally are the result of a symbiotic relationship between fine plant feeder roots and specific soil fungi. It is known that over 90mm of all known plant species which develop roots are Mycotrophic and live in association with their specific mycorrhizal fungi. The fungal spores germinate outside the root and penetrate the root cells of their partner.
The fungi obtain carbohydrates and other substances from their host plants which are produced from the green parts containing chlorophyll while the plants obtain an increase in absorptive root area, of their root system plus the fungal hyphae. This needs to be studied further, for as it stands, if the plants relied entirely on their own roots you would expect them to evolve their own finer roots, a more extensive root system dispensing with the fungi making them superfluous leading to the fungi’s extinction but this has not happened and the opposite has occurred. As it has not happened their must be a stronger benefit to both the chlorophyll producing plant and the fungi than what is presently understood. It is of coarse known that Mycorrhizal hypha networks can be very extensive. Mycorrhizae are also considered to be involved in decomposition of mineral both organic and inorganic materials through the production of organic acids and other substances. Some of these acids and proteins may in fact act like natural penicillin’s to the plants protecting the roots against root pathogens. If the soils are carefully removed from around the roots of orchard trees often a very fine white or pastel grey, web like sheet can be seen. I have also found pale to mid pink. This sheet is the hypha. The hypha are best seen, immediately beneath the mulch.
These fine, broad, sheets then string out in all directions and can increase the total length of hyphae in the ground by many kilometers per kilogram of soil. This means they can increase the actual availability of some mineral nutrients. They may also play a significant role in directly assisting in the conversion of dead plant matter and animal matter, hastening the decomposition in a manner that the elements are in a soluble form for the plant or fungus to absorb or they may be ably actually absorb the minerals before they become water soluble and washed away or taken up by an adjacent plant. If this is the case then the symbiotic relationship would therefore have substantial benefits for both the host and fungus and maybe other decomposers in the upper sections of the soil.
The major nutrient elements influenced by mycorrhizae include nitrogen, phosphorous, sulphur, copper, zinc, iron, calcium and magnesium of which phosphorus is usually considered the most important. It has been estimated that in tropical fruits, mycorrhizal infection of roots can effectively supply as much phosphorus as would be supplied by an application of 500kg per hectare. Muchovej RM (2001) Importance of mycorrhizae for agricultural crops. Institute of Food and Agricultural Sciences, University of Florida, Report SS-AGR-Page 170.
Being adapted to low nutrient soils, mycorrhizae tend to thrive and provide benefit to their host plants only under conditions of low to moderate nutrient availability. For this reason, rock phosphate; which is naturally slow at being released, has been recommended as a suitable phosphate source to encourage mycorrhizal development within citrus orchards. Rock phosphate is the main mineral source of phosphorus available to organic producers. Graham JH, Timmer LW (1985) Rock phosphate as a source of phosphorus for vesicular-arbuscular mycorrhizal development and growth of citrus in a soilless medium. Journal of the American Society for Horticultural Science 110 – Page 489 to 492.
Further to creating increased nutrient availability, the benefits of different mycorrhizae can include enhanced stability of soil aggregates, reduced or increased soil pH or even set up conditions that deter the growth of rival plants or their fungi to the benefit of its partner. Where they are available, legume improved nodulation occurs and nitrogen fixation by the legume is strongly enhanced along with greater drought tolerance.
Plants with relatively coarse roots and fewer hair like rootlets, are usually more dependent upon mycorrhizae for adequate nutrition. Muchovej RM (2001) Importance of mycorrhizae foragricultural crops. Institute of Food and Agricultural Sciences, University of Florida, Report SS-AGR-170.
The different root stocks of citrus show different degrees of dependency on mycorrhizae. Of the rootstocks commonly used in Australia, Troyer citrange, Carrizo citrange, rough lemon (citronelle) and sweet orange are all known to be strongly dependant symbiotic relationship with a particular mycorrhizal. Bevington K (2002) Know your rootstocks. In ‘NationalCitrus Nursery Workshop’. Mildura. (Australian Citrus Propagation Association Inc. http://www.auscitrus.com.au/files/Auscitrus_Nursery_Workshop_Proceedings.pdf
Natural nutrient cycles need to be encouraged in place of soil toxic chemical soluble fertilizes so that the importance of Mycorrhizae can function without interruption. Compaction of soils, herbicides and other chemicals including synthetic soluble fertilizers will all have great impacts on the damage done to the fungi hyphen’s ability to function adequately. This in return will disrupt the role of mycorrhizae in ensuring phosphorus availability and possibly other nutrients are continually available to the plant for its growth and maintenance.
How to Managing mycorrhizae
By preplanting the area with a mixture of good alternative host plants like corn, millet, one of the native Panicum specie, native Aniseed Glycyrrhiza acanthocarpa, native Crotolaria species and soybean all of which help to boost the fungal population in the soil, it is possible to increase the natural level of mycorrhizal inoculation in the field ahead of time before the desired plants are planted. Field trials in America carried out by Panja BN, Chaudhuri S (2004) Exploitation of soil arbuscular mycorrhizal potential for AM-dependent mandarin orange plants by precropping with mycotrophic crops. Applied Soil Ecology26, Pages 249 to 255 found the best crops there, were corn, millet and soybean. I believe the native species mentioned above would also be good alternatives supplying good bulk at the same time.
It is possibly to boost mycorrhizal levels in established orchards and plantations using the above plants initially while the lower growing plants like the Panicum species, millets, Paspalum specie, soybean, and Glycyrrhiza acanthocarpa could be successfully used on older fruit bearing trees and mature trees.
Comparing what we did in the orchard and surrounding orchard management practices several basic differences were noted which would influence the mycorrhizal inoculation rates of the citrus trees, loquats and Sichuan Pepper trees. The latter trees were later removed by the new owner who did not know what they were. The mulch below the Chinese Loquats were always a mass of white Mycorrhizal hypha. Some common misconceptions amongst farmers and orchardists include:
* The diversity of mycorrhizal fungi can be strongly influenced by the diversity of cover crops and manure crops being grown,
* Including what many consider to be weeds in the past in fact adds to the diversity and root interactions,
* These should include plants from the various families including Fabaceae, Asteraceae, Poalaceae etc but not limited to them. The Galium sp. growing within the orchard was always a mass of white hypha. So dense; in fact, that it would cover the whole ground beneath the mulch and extend out into the other surrounding plants.
The more diverse the ground cover, the green manure and volunteer plants the more diverse will be the root interactions and greater the diversity of mycorrhizal species which reduces the soil nitrate levels and extensively increases the biomass levels in the area all of which favour the Mycorrhizae.
Mycorrhizae prefer and develop more strongly in soils which:
* Utilize slow release organic fertilizers which encourage a wide variety of microorganisms in the soil,
* Management strategies which exclude toxic residual fungicides, herbicides and insecticides
* Soils which have a high diversity of organic plant and animal matter,
* Soils that are left in tact compared to tilled soils,
* Soils with better prolonged moisture retention,
* Soils with better aeration and
* Soils with high humic acid.
Mycorrhizae numbers will decrease in variety in soils which are:
* Mechanically cultivated as cultivation severs the hypha allowing foreign diseases to enter or a decline in nutrient uptake,
* Bare ground results in wide variation of temperatures which is not conducive for good mycorrhizae development,
* Bare ground results in wide variation of moisture which is not conducive for good mycorrhizae development,
* Bare ground results in lack of root interactions and subsequently the decrease in mycorrhizae development,
* Use of Copper based fungicides are known to destroy many mycorrhizal fungi,
* Compaction of soils tend to sever or isolate hypha from their host, damage or prohibit good mycorrhizae growth.
Compost
Composting is the deliberate collection of organic matter to hasten the decomposition and or fermentation of that matter by naturally occurring bacteria, fungi and other micro organisms to form humus.
Again; I will emphasize, I personally prefer mulching as I believe it is more frequently encountered on every natural forest floor throughout the world where as composting is only encountered in isolated pockets like eddies where larger amounts of material may gather or where the activities of Megapodes like the Bush Turkey (Alectura lathami) build their communal nests. I believe strongly that a greater range of micro biotic and macro biotic processes are involved over a longer period of time without the fluctuations found when composting. Composting creates a large number of organisms which prefer hot conditions and die off dramatically when those conditions do not prevail. When the compost is spread these organisms die off and the process needs to restart with new organisms which reside in the soil.
The biggest advantage of compost is as is always stated that you have a much smaller volume of matter to shift and lay around the orchard or farm. These same people never mention how much time they spent turning the compost on a regular basis compared to mulching.
Compost certainly has the advantage that it can inject nutrients quicker into the soil where it has been laid where as mulching has a longer period for decomposition and is often spread over a larger area. Like the ducks if you feed them in the one place they fertilize the one place more rather than spread their waste more evenly throughout the farm.
The process of composting has always been regarded amongst most organic agriculturalists as a better method of increasing soil fertility compared to mulching. Compost is not just a source of nutrients and organic matter for the farm but good compost is also rich in soil microbes and as such it helps maintain and or reestablishes soil microbial communities.
Composting is vitally important in establishing healthy trees that can withstand stresses better and establishes a healthy soil that is more conducive to less fluctuation in soil stress resulting in plantations and orchards that produce more even healthier fruit.
Efficiency is the name of the game and composting and distribution is no different. This efficiency will ultimately depend on the purchase price of raw materials, transport cost of bulk ingredients, availability of suitable space, time in turning, timing in distribution and equipment utilization maintenance and energy inputs compared with the cost of chemical fertilizers and distribution. This then needs to be considered against the costs of distributing the raw materials as mulch. Added to this the returns must be calculated on the end product financially and environmental sustainability in the long term.
Working with bulk materials Wilkinson K, et al. (1998) Guide to best practice: Composting green organics. Eco Recycle Victoria, East
Melbourne, Victoria, http://www.sustainability.vic.gov.au/ www/html/508-best-practice-composting-green-organics.asp is an ideal starting point for beginners or professionals wanting to become more efficient.
As we were mulchers we never took composting as serious as some.
Our idea of composting was bring the materials together, adjust the Carbon:Nitrgogen ratio as the materials were layered. Before or soon after the initial heat, the mulch was removed at 90 degrees to the layering with any large pieces (bones etc) returned to a smaller heap for composting and distributing over the seed production area.
Managing the composting process
Compost making is considered both an art and a biological science. Successful composting requires control of pathogens and weeds and the hastening of the natural decomposition and or fermentation process to maximize the retention of nutrients.
Major ingredients for us included hardwood sawdust, animal manures, yogurt, grass clippings with blood and bone, lime and fish emulsion to regulate the pH and Carbon:Nitrogen ratio.Any natural plant or animal origin is acceptable for composting provided off farm non organic materials do not pose any contamination risk or contain any GMO substances.
The C:N ratio can be worked out and adjusted easily. See the chapter Compost and Elements for Growing where we have detailed a large range of materials with their Carbon:Nitrogen ratios and how to calculate additives like blood and bone, lime or fish emulsion to bring the C:N ratio from 27:1 to 30:1 which is ideal and adjust the pH of the mix. Our main use of compost was to break down larger particles and to decompose the yoghurt and other off property matter that may not have been produced organically.
Element balance is important as the continual use of one particular input may increase the level of a particular element. As many organic orchards are in areas where viticulture is prominent citrus growers often avail themselves of the wastes from wineries which can lead to high levels of potassium in the soil over several years.
Our own experience showed after a few years using the hardwood sawdust and Blood and Bone our nitrites and Phosphorous steadily increased that we needed to make a change which we did using fish emulsion and pig manure.
Supplementary ingredients like fungi formula, microbiotic preparations, bio-dynamic preparations, coal humates, crusher dust, ground rock phosphate or trace elements to make more nutrient rich composts. The best time to add these supplementary elements is while layering the major materials.
Particle size: The size of the different materials entering the compost makes a huge difference to the pace of decomposition. The smaller the individual material particles which are in the compost the greater is the surface area which results in a greater area for the various microbes and macrobes to consume and breakdown. Bruising the larger particles is another method which allows microbes and fungi to enter the material and speed up the process of decomposition. This in return hastens the decomposition process. Slashers, flail mulch mowers, chippers, mulching machines and rollers can all aid in reducing the particle sizes and bruising of material. Small particles need turning more as the air spaces between the particles is reduced while large particle sizes allow more air they dry out too quickly so a mixture of both is really the ideal.
Mixing: Effective mixing whether it is by hand or machine is necessary to ensure the different materials are well blended . Good blending allows better moisture distribution, more even distribution of
the various materials and high and low Carbon and Nitrogen materials and the better aeration of the material.
Moisture Content & Aeration: A balance of moisture and oxygen is very important to maintain and support the high levels of microbial activity in rapid decomposition. A good quick method of testing moisture is to take a handful of the compost out. It needs to feel moist without being able to wring any excess moisture out through the fingers when tightly squeezed. Dry compost will slowly cease decomposing until moisture returns while composts that are too wet will induce anaerobic growth, may become putrid and will not kill weed seeds.
Good aeration of the compost mix is critical to support the activity of aerobic microbes while anaerobic microbes have a tendency to encourage detrimental pathogens and fungi. A good balance of fine particle material mixed with coarser material leads to better aeration. Experience with the particular materials available to you, with periodic turning of the compost are the best methods of controlling aeration. Continual mixing ensures that all the material is subjected to the microbial decomposition. However the more the mix is turned the high temperatures that occur at the centre of the heap are exposed to cooler outside air which will have a declining affect on the bacteria and thus will retard the rapid decomposition to a degree. Agricultural drainage pipes have been used successfully when forced into the compost at regular intervals.
Temperature: Prolonged temperatures of 60°C to 70°C are required to kill plant seeds and pathogens. Temperatures of 65°C to 80°C occur naturally in a well constructed effective compost heap with optimum moisture and aeration levels due to the high concentrations of microbial activity. Smaller compost heaps may not be able to maintain these high temperatures as they lose their heat too rapidly because of their large surface area compared to volume. The optimum size of compost heaps or windrows are between 1 meter to 1.5 metres in height by at least 1 meter to 1.5 metres in width. Larger compost heaps have a tendency to become anaerobic in the centre. For rapid, efficient decomposition the compost heaps should be turned when their inner temperatures attain 65°C to 75°C.
Some American standards require windrow compost heaps to remain “between 55°C and 77°C for fifteen days, during which time, the materials must be turned a minimum of five times”. The intention is that all material in a compost heap is exposed to temperatures lethal to pathogens for at least three days during the composting process. Organic Citrus – A Growers Manual by David Mayer
Compost variability: Composts will vary depending on what raw materials have been used, the condition of the soil that they have been grown in, the conditions they have been grown under, the age of the material, the harvesting conditions and how long they have been stored for.
Because of these variations which may be out of the farmers control and the variations in the composting process, composts will vary widely in their mineral and biological properties. For these reasons composts can not be treated like processed fertilizers which have uniform characteristics. The C:N ratio will generally determine the performance of the compost in relation to the nitrogen availability to the plants.
Local compost production: Some of Australia’s larger organic citrus growers produce about 130 to 300 tonnes of compost on site each year and apply it at the rate of 5 to 10 tonnes per hectare per year. These amounts seem to be excessive to me as the years; following the initial 3 year period, we were able to maintain excellent crops and tree vigor on 120 cubic meters of sawdust spread as a mulch over the whole orchard (Maybe around 2 to 2.5 cubic meters of well decomposed compost), 1 tonne of crusher dust spread between the trunks and the tree’s drip lines annually plus our green manures which were slashed and left as mulch. The ducks were probably neutral after estimating egg production take offs and their manure contribution. The other elements were generally locally produced except for the road kills and yogurt which would have added less than 1.5 tonnes in total material inputs not compost weight.
Nutrient release from compost: It has been noted in many research papers that further decomposition of well composted materials is generally slow, and adds little in the way of additional available nutrient in the short term for the plants. Well decomposed compost however does add to the soil in the long term in building soil structure. The provision of available nutrients especially the more volatile elements like nitrates and nitrites need additional, more rapidly decomposing materials such as leguminous green manures or semi mature decomposed compost with a reasonable C:N ratio of 20:1 or less ratio. This is another reason why I am a firm believer in mulching over composting. 15mm to 20mm of the available nitrogen in composts is usually available to the plants in the first year. This nitrogen has a half life meaning that about half the available nitrogen is available to the plants in each consequent year.
With potassium the release is around 80mm in the first year and 20mm in the second year while phosphorus becomes available over three years in a ratio of 40mm, 40mm and 20mm. This is why organic element production is slow and peaks after a few years depending on the soil and plants grown. It also has the distinct advantage if for some reason following the 5th year in theory with nitrogen the farm will drop back to year 1 or better following composting. Again where mulches are added to the surface the growth and distribution of the elements to the soil is slower but the set back in element availability is not as severe as the elements are distributed more evenly throughout the year and a top up would be maintained before all the elements for that year have been depleted by the plants. this is assuming that there was none of the element available to the plants at the start and there is no microorganism in the soils utilizing the excess and microorganism activity still remains constant.
At the same time growers can calculate the amounts of nutrients required annually as top ups or as reserves in their soils.
Animal manures: Animal manures play a useful role in organic crop nutrition. They contain vital mineral elements as well as a large range of complex organic compounds, microbes and organic matter. Organic orchards, plantations and farms require a variety of animal manures for nutrient inputs either as compost ingredients or spread over the surface. If they are spread over the surface they must be from organic sources, free range and contain no GMO’s obviously, synthetic drenches, hormones or antibiotics or produced on the farm as was the case with our ducks. The most common manures sourced externally are poultry manure fresh or pelletized, cattle manure from grass fed or dairy and sheep pellets.
The economic use of manures relies on the availability and costs including transport. Before purchasing or using animal manures, growers should consider the following points:
* The source of the manure is important as manures sourced from non organic sources may be contaminated with GMO, synthetic drenches, hormones or antibiotics. Documentation should be obtained from the supplier with a list of all chemical and biological inputs. This would include chemical wash downs applied to housing both internal and external.
* Manure should be considered like other nutrient inputs, in that an
analysis of its nutrient content is required if an appropriate application rate is to be determined. The nutrient content of animal manures varies greatly. (See section on Composts and elements for growing.) The end results will be variable depending on the livestock diet, whether the manure includes urine, is fresh or dry, new or aged or is pure or mixed with bedding, litter or other material. To be absolutely sure of the elements the growers should obtain an analysis to ensure that the manure suits their particular requirements and is cost effective. We only ever relied on the general analysis of a product and estimated the results using age and bedding material. Over the years Nature sorted it out with the soils organisms with a minimal of fuss. Once the soils reach an optimum the minor differences made very little difference to the end result provided good book keeping is kept on the final product. That is our fruit quality and egg production.
* Organic standards generally require that animal manures be composted before use. This helps to minimize any contamination risks to the organic production. This is more vital on those crops being produced within a meter of the ground. In of our case citrus fruits within a meter of the ground could be contaminated with splash. The overall increase maybe small especially when considering flying fox movements, naturally occurring birds, reptiles and arthropod activities in the orchard but is real. The contamination of manures produced entirely on the property is lower than that of manures secured outside the property.
* Some organic standards restrict the application of animal manure to rates that could be expected naturally if the land was an organic livestock holding. Above all the manure inputs, must not cause degradation or excessive nitrate levels to the soils.
Growers should monitor the situation regarding high levels of micronutrients within the soil caused by the inclusion of animal manures and their accumulating affect in the soil. A cheap affective way to do this is to request a full element analysis of the soil sample when the annual inspection is being carried out. This will be cheaper than requesting a separate analysis.
Micronutrients are often in oversupply when the volume of manure
applied is based on the requirement for macronutrients like the NPKCa Nitrogen, phosphorous, potassium and calcium as indicated earlier. These micronutrients especially salt levels may accumulate to problematic levels also depends on soil conditions. Horticultural production on acid soils should be monitored for this issue annually until a balance is achieved because of the greater availability of many micronutrients at higher pH levels and the changing availability due to natural pH changes as the soils become healthier the pH will move naturally towards the neutral sector of 6.5pH and be more responsive to organic activities.
Microbial inoculants: The purchase and use of inoculants which contain selected strains of bacteria, fungi or other macrobiotic organisms in large numbers are ideal to assist existing beneficial biological activity especially in difficult circumstances which includes:
* More rapid and complete decomposition during composting,
* The most beneficial bacteria for a particular nitrogen fixing legume,
* Specific phosphorus solubilizing soil fungi,
* Fungi and bacteria which prefer high carbon, Carbon:Nitrogen ratio products like hardwood sawdust. We inoculated piles of hardwood sawdust; after an initial aging of a few weeks with a little blood and bone, and found these bacteria excellent for rapid decomposition compared to not using them and adding twice the amount of blood and bone to lower the high carbon ratio.
Australia now has many commercial inoculants available which offer many benefits including increased legume nodulation, B.D preparations, various high carbon decomposition bacteria and fungi and general compost stimulation all of which will aid the organic producers in their efforts.
Commercial fertilizers: There is a wide range of commercial organic fertilizers available in the market place for both domestic and commercial growers. These include pelletized base chicken manures, 100mm blood and bone, sea weed extracts, Fish Emulsion, rock crusher dust, rock phosphate, coal based humic acid and trace elements. Currently many larger companies are selling fertilizers as organic or organic based when in fact they have additives which are not organic by nature. Before using any commercial fertilizers, growers should confirm that the product is acceptable to their certifying body, unless the product is clearly certified by a reputable certifying body.
Commercially available organic fertilizers are generally more costly. Their use needs to be calculated, considering cost of the fertilizer transport and distribution against the manufacturing costs associated with producing their own compost on site. The use of buy ins should be regarded as a short term or gap filling exercise as the main philosophy of organics is to be self sustaining as much as possible.
“The use of off farm fertilizers shall be regarded as a supplement to nutrient recycling, not as a replacement for good soil management practices”.
The reliance on cover crops, green manures, on farm livestock and
composting of wastes should be used to recycle nitrogen and carbon on the farm with a declining dependence on off farm trace elements and micro elements.
Trace elements: Trace elements and micronutrients are permitted by organic production standards as long as they contain no prohibited substances and are used to correct a nutrient deficiency. It is the producer’s responsibility to show that a need exists; through leaf analysis or documented deficiency symptoms and to confirm that the products to be used comply with the relevant standard. Magnesium, manganese, iron, copper and zinc chelates with copper and zinc oxides are commonly used to correct nutrient deficiencies in Australia. They are listed as permissible inputs by the various standards.
Nutrient ‘Losses’ from Crop Removal & Leaching:
There are numerous manners in which nutrients especially trace elements are lost or removed from the orchard. This decline makes them unavailable for recycling and reuse by the crops, cover crops and soil organisms. While some are inevitable, others can and need to be minimized through good organic practices. The various methods of decline are as follows:
* The most common loss is associated with harvesting of the crop. The removal of nutrients has been discussed and for example is approximately 1.2 kilograms of nitrogen per tonne of citrus harvested and removed from the orchard,
* Leaching through poor soil management and irrigation is the second major reason for nutrient loss especially amongst the more soluble and volatile elements like nitrogen and calcium,
* The nutrients delivered and maintained in the leaves, fine roots are continually recycled as those organs die, decompose and expand. Elements; in particular on plantations and in orchards, are permanently locked up in the trunk, major branches leaves and roots, and as a result are unavailable for recycling once stored in these tissues. It is estimated that between 200 and 250 kilograms of pure nitrogen per hectare is permanently locked up in mature citrus trees. Most hard leaf orchard trees of similar size and plantation trees exhibit similar properties. Larger trees like Avocados probably exhibit similar tie ups proportionally to size.
Nitrogen in particular is easily lost from the orchard through volatilization as an ammonia gas or leaching of water soluble nitrites and nitrates through the soil. High humus soils and soils with high organic matter will buffer the affects of leaching because they have a far greater water holding capacity resulting in far less leaching and as a consequent far less loss of nitrogen and other easily soluble elements. Incorporating or digging the compost into the soil will also assist in reducing gaseous losses compared to surface applications of compost. High carbon mulches on the other hand decompose utilizing nitrogen from the soil. As the micro and macro organisms move the mulch deeper into the soil the nitrogen and other more volatile gases are released as either ammonium or sulfides. Healthier soils also have the benefit of tying volatile elements up which quickly form less volatile compounds in the soils or are buffered by the by humus and humic acid. Incorporation into the top layer of soil improves the mineralization of Nitrogen by 64mm for the pellets and 8 fold for composts.
Loss of ammonia from the surface applied compost and pellets continued for at least 180 days. These losses mean wasted time, money and nutrients, and increased environmental impact compared with green manures grown on the site where the cycle is in a balanced state between volatility losses and soil organic matter decomposition. This would also be lowered where a larger number of macro organisms live like worms which many feed from the surface and defecate below the surface. These are all paramount issues for the organic grower especially the small crop grower who has to continually introduce compost to the soil rather than slash and allow it to decompose where it lands.
Carbon mulches can reduce nitrogen losses by being spread over the top of high nitrogenous composts or green manures meaning less Nitrogen is lost as ammonium if it is spread into longer grass such as the cover crop or is mulched over immediately following its application. We incorporated the long grass and spreading of the sawdust immediately after applying more volatile inputs across the surface. The use of high carbon mulches to capture the volatile ammonium is only affective if the sawdust or mulch is damp or moist.
Another method of reducing leaching of nitrogen, phosphorous and other water soluble elements is to incorporate deep rooting forage crops like rye, oats, wheat and Paspalum into the pastures, orchards and plantations. These crops will recover nutrients from lower levels and return them to the surface as slashings or fodder crops to be again composted, mulched and decomposed. In the mean time the stems and leaves act as a storage house for the elements until they are harvested and mulched or composted.
The astute positioning of buffer zones is another way of trapping nutrients being eroded or leached from the farm. Here sub shrubs especially legumes can be used to trap and store the nutrients until they can be returned to the farm. This method of trapping and return is common in Asia.
Salinity dramatically increases the rates of nitrate and many trace element leaching as the elements chemically react to form compounds which are more easily leached. Metallic chlorides are the best examples like Iron into ferric and ferrous irons will quickly form iron chlorides. Again high humic acid soils and soils with plenty of organic matter will help in tying up (buffering) any excess elements buffering the pH and the soils during periods of high rainfall, strong winds or mechanical methods. Again the incorporation of deep rooting forage crops like rye, wheat and Paspalum into pastures, orchards and plantations will lower the incidents of leaching buffer the pH and minimizing stress.
Nutrient pollution
Nutrient pollution is not just a chemical farming problem but also one where stockpiling of raw materials exist, processing occurs and the application process is carried out. Nutrient rich materials like compost and animal manures can pose a risk to ground and surface water contamination. The more readily soluble elements like nitrogen and phosphorus are particularly prone to leaching. This leaching and weathering is a waste of finances and effort. To avoid causing or creating pollution along with any associated environmental impacts and to comply with good environmental practices and organic standards and standards conditions:
* Site planning is critical. We placed our stock piles on the upper elevation of the orchard so that any spillage or wastage would be contained within the first few rows of the orchard,
* Effective storage of raw and composted material to prevent excessive wetting and leaching of water soluble components. Tarps could easily be applied if prolonged wet season existed or as we maintained the bulk raw materials were gathered at the end of the wet season where moisture was more easily controlled,
* Effective composting to avoid excessive free nitrogen in the finished
Product. In our case we used higher Carbon:Nitrogen ratio materials where all the nitrogen was tied up in the reactions,
* Lower application rates were carried with partially decomposed material to avoid excessive concentrations of the elements and it was spread over the green manure slashing in early spring,
* Efficient irrigation practices to minimize leaching of nutrients beyond the tree root zone. In our case as the orchard matured no additional irrigation was ever required,
* Completely covering of the land surface with cover crops ensured that mulches were less likely to suffer from wind or water erosion.
Nutrient uptake and use
Nutritional uptake by a tree varies on the type of tree and many environmental factors like the season, the availability of nutrient (pH), the moisture content of the soils, temperatures, even to a degree the pests, fungi and bacteria in the soil and what herbs are being grown in the inter rows as they can be either competition or symbiotic partners.
Nutrient accumulation in fruit
The peak rates for accumulation of the major nutrient elements for most trees coincides with rapid fruit cell division and expansion, and root growth which is prior to the fruit actually ripening.
Nitrogen mobilisation within trees
It is important to note that in perennial trees, up to 85mm of the nitrogen which is required for flower buds, flowers, developing fruits and new leaves to form is already stored within the trees. These nitrogen reserves were deposited during the prior growing season. Nitrogen for example is stored in the leaves, branches, trunks and roots, and is mobilized during growth flushes and flowering. Even in over fertilized mature trees with abundant available nitrogen in the soil, about 80mm of nitrogen in young fruit and leaves comes from tree reserves and the remainder from recently absorbed soluble nitrogen. 1) Wallace A, et al. (1954) Translocation of nitrogen in citrus trees. Proceedings of the American Society for Horticultural Science. 64, Pages 87 to 104.
2) Boaretto AE, et al. (2006) Efficiency of nitrogen fertilization on citrus orchards. Acta Horticulturae 721, Pages 331 to 336.
3) Legaz F, Serna MD, Primo-Millo E (1995) Mobilization of the reserve N in citrus. Plant and Soil 173 (2), Pages 205 to 210.
These research papers prove to a large extent that soil nitrogen and nutrients should be available to evergreen trees during the last growing season and off the physically visible growing season as well as the present growing season. It is the non flush periods that the tress are accumulating the resources in a more steady pace in readiness for the following flush. The idea of slashing the tree inter rows and or laying of compost 3 to 5 weeks prior to the flush is to cater for the additional 15mm to 20mm the trees need at the time of flush or flowering to fruit set and again at rapid fruit development. Most of the available nitrogen from the slashing is available for the trees use in the third to eighth week following slashing. This meant that there was good nitrogen levels available for the trees in the soil during the non growing period when the trees were in a state of building up reserves.
Nutrient uptake by roots
Research conducted by Iwakiri T, Nakahara M (1981 ) Nitrogen fertilization programs in Satsuma mandarin groves in Japan. Proceedings of the International Society of Citriculture 2, Pages 571 to 574 using radioactive nitrogen applied to the soil found that the rate of absorption of nitrogen by citrus roots was lowest during winter to early spring dormancy and increased during the mid spring flush and flowering and the summer growth flush. Peak absorption was in late spring to early summer during fruit set for Valencias and mid late autumn for mandarins.
I would expect these times to be variable with different orchard trees as the peak periods appear to coincide fruit set to early expansion which in our case was mid to late spring. (Clemantine ripe early spring Imperials, Emporers, Navels, Lanes, Cumquats and Grapefruit late spring with Seminola in early summer.)
This makes sense, as the nutrient absorption and translocation efficiency of citrus roots is inhibited by low soil temperatures below 13°C. Bevington K, et al. (2003) Fruit size management guide Part
1. Australian Citrus Growers, Mildura, Victoria. http://www.
australiancitrusgrowers.com.au/aspdev/ Soil temperature to a depth of 200mm in the Nana Glen district is typically below 13°C from late June to early September; long term averages, thus increased absorption of nitrogen from spring onwards also coincides with higher soil temperatures.
This research paper again proves to a large extent that soil nitrogen and nutrients should be available to evergreen trees during the previous growing seasons and off physical growing season as well as the present growing season from early spring through to early winter until the fruit has reached maximum size. Nutrient availability in deciduous trees would also be required from about 3 weeks prior to the spring flush of leaves through to when the leaves begin turn colour and fall in the case of persimmons and the Rosaceae fruits like apples, pears, plums and cherries.
Therefore over 80mm of the total organic nutrient is best available from September to early June so the trees can most efficiently absorb it for growth and storing in tissues ready for use. It also reconciles that probably looking at our graph that 75mm of this 80mm uptake occurs in the first 3 to 4 months. Organic fertilizers, compost and mulches are most actively releasing their nutrients for plant uptake during the periods in which the plants are most likely absorbing nutrient from the soil. The applications of compost and mulches are best done in late winter and topped up again in late summer or early autumn. Once our orchard was established mulching occurred in late winter to early spring immediately following harvesting. We always endeavourer to finalize the spreading of mulches by fathers day.
Our first slash of the inter rows always occurred just prior to the spreading the mulch. The growth over winter and with the first warm weather initiated better clover and rye growth which gave a maximum biomass prior to spreading the mulch.This released vital nitrogen into the soil with the he nitrogen released from the decomposing roots and root nodules and coincided with bud swelling of the individual cultivars.
Water Harvesting on site as per new regulations
The collection of water, water management and the adoption of efficient irrigation design techniques are all of paramount importance not just to organic producers but all agricultural users. Water is a vital component of the natural and agricultural landscapes and is coming under increasing pressure as a valuable resource around Australia. This pressure will increase as droughts become more prevalent with global warming in many locations. The organic industry recognizes this and aims to manage water better by carefully:
* Providing the crop’s water requirements efficiently by using less water,
* Preventing saline conditions from accumulating to harmful levels in the soil means monitoring and using proven non solidifying methods,
* Maintaining sufficient soil moisture to support green manure or cover crops and soil biological activity by increasing soil humic acid on the farm and surrounding corridors,
* Minimizing any negative environmental impacts from over use of water on the farm.
Organic standards are also concerned with:
* The environmental impact and management which includes the minimizing of any negative impacts of the water use from the point of extraction, use, disposal and with the interference with natural flows.
* Resource use efficiency to minimize water wastage,
* Impacts of water use throughout the farm which includes the quality of the water, soil, weed, disease management, salinity and possible natural contaminants.
Environmental management
Organic agricultural philosophy is to maintain and improve the health of our natural water systems including ground water, rills rivers, streams and oceans. Organic producers need to satisfy their certifiers that they have a plan in place to protect the environmental criteria required by demonstrating their practical approach to water conservation and management:
* Maintains environmental flows and the quality of riparian zones and
natural wetlands. We demonstrated this by having a 4 year back up supply which allowed for a natural flow into the dam which was equal to the natural flow out of the dam following the filling of the dam. Our overall use was negligible especially following the sixth year of growth.
* Avoided contaminating groundwater or natural surface water systems when reclaimed water from drainage or waste recycling is used,
* Avoids soil erosion, water logging and salinity to all down stream sources including rills, creeks, streams, rivers, estuaries and oceans,
* Avoids the leaching of nutrients from the property into groundwater or natural surface water systems,
* Ensures that any surface water leaving the farm is of equal or better quality than that entering the property.
These issues are largely addressed by good water management on the farm, in the orchard, plantation, station or dairy.
Resource use efficiency
Organic producers are required to use water efficiently to minimize
wastage and minimize the efficacy of this increasingly valuable resource. Excess water use has implications for environmental flows, negativity on removal of nutrients, aids in soil compaction, soil pH and energy consumption. Management of environmental flows is now being addressed nationally with regional and local level inputs. At the farm gate increased humic acid levels can eliminate or at worst lower water usage phenomenally.
Choice of Irrigation System.
Irrigation systems are as varied as the farms they are to water. Each needs to suit the individual characteristics of the individual farm when considering such things as soil type, water quality, water availability and climate, temperatures and humidity, as well as the grower’s objectives in relation to organic management of the soil, crop nutrition, ground covers, pests, diseases and even the source of the water.
The correct irrigation system takes into consideration, all the above aspects coupled with the advantages and disadvantages of each system on merit:
* Furrows are the cheapest but not recommended on light, unevenly textured soils or uneven ground because of wastage and difficulty in obtaining uniform water distribution.
* High pressure overhead sprinklers suit cover crops, larger areas, garden beds and can be used to broadcast nutritional programs but suffer relatively high evaporation losses, are prone to uneven water distribution due to overlapping and can increase tree stress if the water contains dissolved salts. They are less expensive than low pressure system.
* Low level low pressure sprinklers suit cover cropping and broadcast nutrition programs but require good canopy and groundcover management to minimize interference with water distribution, and are more prone to mechanical damage.
* Low pressurized systems use low pressure micro jets and are more costly but allow more precise applications of water with low evaporation rates. They can easily be placed under individual trees and are highly efficient. They are ineffective on wind days, tend to suffer blockages especially from ants when not in use and are more prone to mechanical damage. Low pressurized systems require maintenance or treatment to prevent blockages.
* Drip lines provide the highest water efficiency but require water on demand is less suited to nutrient programs based on broadcast compost or manure and makes cover crops more difficult to establish and maintain in dry districts. Drip irrigation lines also require maintenance or treatment to prevent blockages.
Drip irrigation systems may require some sanitation treatment to
prevent algal growth that can block dripper outlets. Chlorination using sodium hypochlorite or hydrogen peroxide are suitable and are presently acceptable to Australian certifiers but they are under review and should be checked prior to use in the future. Most modern drippers can have their tops removed so that they can be flushed out which is more labour intensive but less polluting and less costly. Maintenance of irrigation systems is critical for the efficiencies to be maintained which includes the correct application rates and to avoid water wastage. Wastage and efficiencies; once constructed, is in the form of restrictions or leakages. These include blocked outlets, blocked filters, crushed pipes and “weeds” that interfere with sprinkler water distribution or leaking pipes, missing sprinklers or faulty valves.
By installing a removable plug or a faucet at the end of each row allows for easy flushing of the system
Irrigation System Design
Correct layout of the system is necessary to ensure even coverage of the irrigated area. Correct sizing and layout eliminates wet and dry areas ensuring all the trees or area receive equal coverage of water.
Irrigation Scheduling
Accurate irrigation scheduling ensures the crops are neither over watered or under watered which can cause stress or pathogens to increase. Accurate watering leads to higher crop yields and better efficiencies. Over watering can also lead to not just water wastage but nutrient leaching and raised water tables which may result in salinity problems. Irrigation scheduling requires knowledge of the soil’s water holding capacity, the crop’s requirements and the feeder root depths.
Scheduling also requires monitoring of the orchard water balance or moisture status, through actual applied water, rainfall, evaporation, soil moisture levels and crop consumption under different conditions.
Impacts of Irrigation Systems
Water use can have direct impacts on the crops health, quality and environmental factors up stream and down stream. To minimize any potentially negative impacts within the ecosystem producers need to demonstrate that any negative impacts of irrigating like leaching, salinity, lowering or raised water tables have been addressed with appropriate measures in place to mitigate the impacts or at least minimize them. It may be necessary to monitor such factors as:
* Soil and groundwater quality within the orchard and on adjacent land,
* Local water table levels are maintained or returned to previously normal known levels where possible,
* The volume and quality of irrigation and drainage water is maintained.
Testing off-site water sources for Contamination.
Irrigation water is always a potential source of contamination by neighbours for the organic producer. Australian organic standards require that off site water sources including shared public sources like channels and rivers be tested for contamination regularly. The type and frequency of testing is determined by the specific situation. In districts where public water sources are routinely tested, growers may be able to obtain the information required on water quality from the local water authority.
Cautious use of Reclaimed Water
On site water recycling is encouraged however, the use of off site reclaimed water is tightly regulated by organic standards because of the risk of contamination with chemicals, pathogens, salts or heavy metals to the property or environment.
Growers should note that some certifiers do not permit the use of water reclaimed from industrial or human wastes. Where reclaimed water is permitted, testing is necessary to ensure that any contaminants like pathogens, heavy metals and herbicides or pesticides are all below acceptable levels. Most reclaimed sewage water contains higher levels of lead or chrome which are unacceptable to organic standards. Reclaimed water is also regulated by Environment Protection Authorities (EPA’s) and producers wanting to make use of reclaimed water for irrigation should familiarize themselves with the requirements of their state EPA and testing procedures in place. Treated water from industrial areas are more prone to the higher levels of heavy metals where as treated water from rural towns where industrial areas are minimal release better quality water into the streams and rivers or make it available for reuse projects including farms and orchards.
Drainage Management
Soil leaching is only necessary where salt levels around the root zones are increasingly high and indicate poor past irrigation management methods have been in operation. Deliberate soil leaching is generally carried out at the end of the wet season to transfer accumulated salts deeper into the soil or away from the property and should be considered as a last resort as it may only transfer the problems to another location. Sandy soils and sandy loams respond better to soil leaching than heavy clays. Before soil leaching is carried out it is better to improve water efficiency with programs to increase the humic acid content of the soil, reduce salt levels going onto the farm by decreasing irrigation, decreasing evaporation and or changing or improving the water quality of the water source.
Improve leaching efficiency through irrigation includes:
* Allow the whole root zone to dry out to the refill point before irrigating, to keep salt moving downwards,
* Maintain a surface cover of mulch or cover crop residue to improve
water infiltration and minimize evaporation,
* Apply leaching irrigation is best achieved at the end of winter when the soil profile is already moist from pure rain water and the evaporation rates are low,
* Trickle irrigate avoiding surface ponding or surface run off. The saline water must be disposed in a manner that does not affect downstream users or the environment which can limit the efficiency of this technique.
Alternative methods of salt removal is to use high salt tolerant plants:
* To maintain a surface cover of mulch that improve moisture penetration and can be removed from the affected area, composted and returned to another area or removed off site. Some plants that could be used would be Acacia cultiformis for a tall growing shrub, Atriplex amnicola, Atriplex cinerea, Atriplex nummularia or Rhagodia candolleana subsp. candolleana for a lower growing shrub or Fimbristylis sp. in particular Fimbristylis polytrichoides which is strong growing grass that can remove salt from the soil. Feeding the foliage to forage animals that are used for meat will also remove some of the salt off site. What values of salt can be removed through egg production is unknown to the author.
Soil management.
Soil compaction through over watering, surface run off through surface caking or compaction and erosion are normal cycles in high rainfall areas and where irrigation is carried out on a regular basis. The easiest way to resolve soil compaction is through groundcover and green manure management, timing of cultivation and improving the physical soil conditions. To reduce the physical impact of water on the soil and improve water infiltration rates the use of ground covers and green manures is second to none. Further the addition of copious quantities of humic acid via composting or mulching improves water and nutritional buffering and water absorption. The greater the absorption rate of the soil in return reduces the energy costs, maintenance costs and labour time costs associated with irrigation management. This in return reduces nutrient loss through leaching, reduces salt increasing in the soil and the associated pollution of ground and surface water runoff.
Pests and Weed Control
Foragers Paying Their Way While Reducing Costs
An entire holistic approach is required in agriculture to move to sustainability and away from toxic substance approach where managerial skills rely heavily on and increasingly, stronger and more virulent methods in attempts to eradicate pests and weeds. The replacement of “Hard Toxic” chemicals with “Softer Biodegradable Compound” alternatives, including microbiological pesticides, plant extracts and new cultivation approaches is profoundly embraced by organic producers. Some of the disadvantages of the presents system need to be looked at so an appreciation of the softer sustainable approach can be fully realized:
* Many treatments have undesirable affects on non target organisms and the broader environment,
* Cultivation in particular is very disruptive to soil structure, moisture and soil micro and macro organisms,
* Many treatments are relatively long lasting in the soil and environment – arsenic, lead and organochlorines to mention a few which were heavily used and accepted to be relatively safe prior to their banishment,
* Seed banks where seeds are long lived produce new flushes long after treatment, often years or decades later,
* Genetic Modified Food products are inadvertently evolving pests with stronger resistances towards the GMO crops. – genetic Variability supports variability in control mechanisms against pest resistance and against applied pesticides,
* The impact of pesticides on beneficial non targeted species results in pest resurgence or development of secondary pests prior to the non targeted species being able to reestablish itself/themselves following toxic chemical applications,
* The energy costs, environmental costs, health cost and labour costs of petroleum based inputs far exceeded those of most natural products found in nature. The costs of monitoring, purchasing natural carnivorous bugs or fungi spore for releasing with no consequent health and environmental impacts is far cheaper and usually far more effective long term,
* The storage and disposal of containers is a concern with poisons being inadvertently spilt,
* The second highest cause of child poisoning occurs on farms often hours away from hospitals,
* The habitual reliance on ever increasing toxic chemical sprays and associated secondary developments distract producers from the importance of careful observation and thought provoking alternatives which nature has developed over the eons.
The challenge for agriculturalists is understanding, “Why a certain pest is a pest?” and not that it is there. To address the underlying weaknesses in the farm ecosystem, orchard or station which created the pest or weed status in the first instance is the first step in solving the problem not deferring the problem. The underlying fundamentals in the system have obviously been moved to create an environment that is more suited to the pest and weed rather than to a balanced relationship between plants, crops and animals. This move creates a position that favours an individual where it dominates the environment and becomes an issue or is problematic.
Forest or an Orchard
Long term sustainable solutions, must focus on restructuring the farm system so that it closely resembles a natural system. In our orchard we totally integrated the orchard into the surrounding Eucalyptus forest. We had two independent forests and a transitional zone growing together as one. This is normal in nature for example where a Eucalyptus sp. forest has an integrated zone or transitional zone before it becomes a Casuarina sp. forest for example. Many of the organisms that inhabit the Eucalyptus forest are different to those that inhabit the Casuarina forest yet blend together in the transitional zone which creates greater diversity. The herbivores and carnivores live side by side in a chaotic balance both striving for survival while the weeds succumbed to competition and suppression over a period of a year or even a decade. The climatic conditions, habits and micro niche performances were all evaluated and noted how they all perform at different times of the year to their benefit and ultimately to our benefit.
To this end, we used our mandarin trees as one forest and the existing well established moist Eucalyptus forest as the other forest. The Eucalyptus trees supported Glycine sp., Hardenbergia sp., Hovea acutifolia, Indigofera australis, several Poaceae sp. and Themeda australis while the Mandarins mainly supported Trifolium repens and Paspalum sp. The inter zone between the 2 forests was dominated by Citrus australasica, Boronia umbellate, Pittosporum multiflorum, several Senna sp., Cayratia clematidea and Cissus hypoglauca. (Citrus australasica, Boronia umbellate, Pittosporum multiflorum are all native members of the Rutaceae family so were all natural substitutes for the citrus trees and well suited for the inter zone between the Mandarin forest and the Eucalyptus sp. forest.)
We were able to completely escape the chains of toxic chemical conventionalism and return entirely to nature for every experience, every pleasure and produced the best mandarins and lemons in Australia, coupled with the highest production rates in our district and probably Australia. By completely integrating the 2 forests into one, we were able to maintain a 100mm approach to sustainability without any reliance on herbicides, insecticides or fungicides. Most our inputs supported the local native indigenous micro organisms in the soil with the noticeable exception being the small amounts of returned yoghurt we used in the initial stages of composting. Treating our orchard as a Rutaceae forest we broke away from convention and instead relied entirely on the local indigenous organisms. I sincerely believe, this was the key to our success.
The use of pesticides and other toxic “Treat the Symptoms Methodology” were never considered a part of our regime. These approaches are unsustainable and should not be considered the first line of defense or in fact any line of defense. Professor Stuart Hill on the other hand; ( Hill. SB. 1998 Redesigning agroecosystems for environmental sustainability: a deep systems approach. Systems Research and Behavioral Science, Page 391 to 402.), suggests that the approach to sustainability can pass through several phases on its way towards sustainability. This may be acceptable in an area that is not fortunate enough to already have such a rich source of vegetation and biodiversity at their fingertips. Our approach moved directly to his final stage armed with all the knowledge with an already established bushland of over 45 years growth. On every occasion we looked intimately for solutions through nature and what nature was telling me. We used her ecosystem on our door step as our guide our teacher and our inspirational leader.
Professor Hill refers to citrus producers; in general, as operating in the “Efficiency” or “Substitution” phase without ever moving to the full sustainable stage. Organic citrus producers are therefore in a sub pure organic stage as long as they remain in the “substitution Phase.” Because of their philosophical approach or restrictions imposed by organic standards or both they find it difficult to cross the final hurdle. “Their aim should be to move towards the final stage where modification or design of the orchard system allows for greater robustness and stability without the need for intervention by the grower. To take this step, growers should use organic standards as the foundation for building better production systems, rather than simply complying with their minimum requirements as often occurs.”
Remember Organics is not farming conventionally and substituting organic fertilizers in place of chemical fertilizers, herbicides and insecticides. It is an overall transition to total sustainability.
The photo here is of a mature pear, cherry and plum orchard, integrated with ducks. At the edge of the Bei Bei Shan National Park Wilderness area in central China, on the higher slopes; on the left, and on the opposite ridge. The mature trees are grown organically and rely wholly on the methods I have discussed above. There is no permanent water supply. They rely on terracing and contours to preserve rainfall and orographic precipitation from the almost daily fogs on the steep slopes.
Whether organic growers are afraid of the final stage or not is unknown; as few growers apart from a few permaculturalists have ventured into it. The philosophical objective of organic management is to develop a naturally “balanced” systems where the maintenance is carried out entirely by nature alone, requires no intervention but needs high levels of confidence that nature has all the answers and can carry out all the growing work that is required to the point of balancing pests and predators and utilizing annuals and monocotyledons; grasses, as they were intended at the first stage in covering bare earth and increasing the fertility in a sustainable quick manner so that higher order plants could flourish.
Weeds
In our natural system weeds were construed as a vital niche within a society of higher order plants. Their prevalence is dictated by the weather, soil conditions and changes in microbiological activities. They are not to be feared as every plant has its weakness and every ecosystem has its strengths to suppress any explosion in numbers. If we address the underlying weaknesses we have created we help to suppress the imbalances. If nature is given time she will suppress the imbalance. How we hasten this movement depends on the property, the species and what it is doing outside its natural habitat. Given adequate water, healthy soils are rarely if ever bare. Our orchard; following the initial poverty poor soil years never had a bare patch but exploded in a never ending growth of green manure, green mulch and duck feed. Signs of disturbance and imbalance were never experienced and in fact were often exploited by rapidly growing species that we consider as green opportunities. The orchard or plantation manager can choose to:
* Maintain a soil cover of mulch of desirable plants to help suppress the less desirable species,
* Continually struggle to maintain an unstable and untenable situation where bare soil predominates. Most orchardists prefer to maintain sown annuals, volunteer annuals, grasses, annuals or green manures in the inter rows as cover crops. These can be slashed/grazed as necessary adding to the tree row mulch.
Primary Pests
As the tractor and ripper are essential for developing healthy soils, a good 10 power hand lens, along with a note pad, pencil and camera are essential tools for monitoring the soil, leaves and inner circles of nature. The hand lens offers instant evaluation, while the notepad allows for better more accurate referral evaluation. The camera records the facts at a particular time, transferring these facts to history for future evaluation. Only the camera records the facts accurately without distortion unlike the memory which frequently betrays our recognition and reconstruction of past events. Problems and solutions start small before they become large and often overwhelming to us mere mortals.
First and most importantly thing is KNOW YOUR ENEMY, KNOW WHEN THEY ARE LIKELY TO ATTACK, KNOW THE FIRST SIGNS BEFORE THEY ATTACK AND HARBOUR THEIR ENEMIES, YOUR ALLIES.
The enemy here is the 28 spotted ladybeetle, Epilachna vigintioctopunctata. This is the stage to prepare for war.
The eggs are the first sign that an attack is imminent. This is the time to act.
The first signs of leaf damage indicate the enemy has started to advance.
All farm producers should avail themselves of the following valuable publications to effective, efficient and environmentally sound organic pest management by monitoring, identification and recommendations for control as well as using the other sections of this Net Book:
* Garden Friends. Mellis AF (2004-2015) The Bible of Botany – Garden Friends,
* Plant Diseases & Viruses. Mellis AF (2004-2015) The Bible of Botany – Plant Diseases & Viruses,
* Citrus pests and their natural enemies,
* Integrated Pest Management in Australia. Smith D, Beattie GAC, Broadley R (1997) ‘Citrus pests and their natural enemies: Integrated Pest Management in Australia.’ Queensland Department of Primary Industries and Horticultural Research and Development Corporation. Brisbane,
* The Good Bug Book. Llewellyn R, et al. (2002) ‘The good bug book : beneficial organisms commercially available in Australia and New
Zealand for biological pest control.’ Integrated Pest Management P/L for Australasian Biological Control. http:// www.goodbugs.org.au/
Australasian Biological Control agencies are another valuable area where producers can receive personal information assistance and remedies without being exploited:
Australasian Biological controls at http://www.goodbugs.org.au
Biological Services Email: info@biologicalservices.com.au
www.biologicalservices.com.au
Bugs for Bugs Email: info@bugsforbugs.com.au
www.bugsforbugs.com.au
While we used and refer to “bugs for bugs” because we had first hand experiences using their services on our farm we have been informed by other growers that all the above firms are reliable efficient and cooperative in their approach to agricultural and horticultural producers.
Primary pests are those pests that directly attack the crops being grown as compared to those that follow the initial attack and often create the secondary or tertiary problems. To demonstrate a secondary problem the noisy minors (Manorina melanocephala) moved in and consumed ripe fruit in a small corner of the orchard. On monitoring the birds activities closer it was found that they were eating fruits which had already been damaged by Rainbow Lorikeets (Tricoglossus molluccanus) Once we controlled the Lorikeets the Noisy Minors also abated. Control was made by planting a few sacrificial plants adjacent to the bush. The lorikeets felt safer there and responded by not being harassed. The noisy minors of course followed suit.
Herbivores in natural ecosystems maintain a balance with their natural predators. As conditions arise that favour the herbivore their numbers increase. Their increased numbers then favours the predator though it may be a few days or a week later an increase is inevitable. Also remember at times the opposite also occurs where the predators number may increase, probably as a result of a higher order carnivore being suppressed, causing a decrease in the herbivore numbers resulting in a temporary overall decrease in both herbivore and predator numbers.
Aiming to develop or retain this balance is a far more rational approach than aiming for the herbivores eradication with the use of toxic sprays. “It is often more difficult to do nothing than to be seen to do something when nothing will work just as or more effectively.” Modifying the ecosystem, environment or niche corner to favour beneficial species helps to achieve the required balance. Modifying the ecosystem can involve:
* Planting, protecting or enhancing wildlife corridors to provide shelter or over wintering dens and warmth,
* Reduce wind and dust,
* Induce the growth of certain plants for attracting the herbivores and consequently the predators of plants you grow as a crop- Decoy plants,
* Allowing flowering and seeding of cover crops in inter rows and wild life corridors to provide food for herbivores, predators and parasites so that a balance is maintained all year,
* Growing sacrificial plants plants for easier monitoring,
* Eliminating or minimizing sprays of any sort that disrupt beneficial predatory activities.
It is important for producers, especially those new to organics to grasp the concept of embracing habitats that first support the pest or enemy which in return attracts the predator your accomplice. Embracing a habitat that supports the enemy like we did by using Boronia umbellate (Citrus butterfly), Pittosporum multiflorum (aphids and psilids) and Citrus australisica Honey eaters and lorikeets is similar to using a bait or lure. These plants are a first choice for the many predators that may inflict damage to the Mandarin trees. Here I could observe them and monitor the build up of their predators with no or little noticeable damage being done to the orchard.
Our first natural observation was made in the early years of development. I was fostering Boronia umbellate in the transitional zone as it was a rare and endangered species. Come spring, I noticed dozens of citrus butterflies (Papilio aegeus) flying over the orchard but none stopped to lay their eggs on the young citrus tree leaves. I followed the butterflies and noticed that they were all fluttering around stopping to lay their eggs in the more protected area of the transitional zone landing on the Boronia umbellata. This struck me as an obvious advantage that the 300 to 400 Boronia shrubs were far more enticing to the butterflies than 1,200 mixed Citrus trees and the Microcitrus australisica.
If monitoring and harbouring both the predator and herbivore in balance away but near to the orchard the grower places him or herself in a very favourable position. The beautiful, Swallow Tail Orchard butterfly (Papilio aegeus) is a great example of the use of decoy or sacrificial plants in use. In consequent years the butterflies rarely laid their eggs on the Mandarins, instead preferrng Boronia umbellata Citrus australisica which is obviously one of its natural preferred food sources. The Papilio aegeus butterfly always appeared in mid spring in our area. Too beautiful to kill which was wonderful to see them opt for the natural host trees in the intermediate zone.
Similarly Toxoptera citricidus and Toxoptera aurantii are the two main deep brown black Aphids which are seen inhabiting Citrus orchards especially the former. Again a few naturally occurring Dodonea sp. including Dodonea triquetra and Dodonea viscosa attracted the aphids prior to them moving onto the orchard which gave the predators a chance to move in and start their kill. The aphids again after the first year when we bought Green Lace Wing were never an issue thereafter as the Green Lace Wing with several species of Lady Beetles maintained a healthy off season number which reacted quickly to any increase in Aphid specie numbers. Aphid numbers need to be monitored with the onset of growth flushes on the Mandarin trees.
Identification:
Know the Pest and Beneficial Species in your District
Correct identification of the target species whether it is a problematic plant, pest or disease is essential to good control strategy management plans. At first it may seem that there is a never ending stream of bugs determined to end your foray into agriculture but that soon changes. Correct identification of pests allows you to select the correct decoy and attractant plants in the future as well as correct effective control mechanisms. It also allows for the correct beneficial predator to be purchased or to construct a suitable safe haven within the wild life corridor. With these two points in place observational prowess is made even easier. Monitoring is a powerful tool for growers as it allows them to safely work out in advance, what biological control/s; if any, are needed to be activated on the farm and monitor the positive or negative impacts of management actions on the pests and desirable species.
I have said it in other Chapters
“Know Your Bugs – the Good, the Bad and the Ugly”
Monitoring is really another word for getting to know what your beneficial predators and pesky herbivore species are up to. Too often we become infatuated with the problem some ones and spend too little time learning and understanding the habits of our allies in the bush. Are the pests really ready to attack, subsiding or just going about their day to day activities. In monitoring, the farm actions can often be deferred especially when other tools like weather patternsspecific pest knowledge, crop type, time of year and geographic region are all considered. For us the growing of beans was an absolute no go zone after New Year as January always herald the uprising of this notorious little stink bug Nysius vinitor that sucked the snake beans dry. Before they encroached onto the farm the signs were there for all to see on the Senna sp. seed pods and many Asteraceae sp. This is when we stripped the beans of all their fruit and mulched the rest of the plants before the first invasion started. We could plan this to the day. It did not prevent the loss of the crop but allowed us to harvest everything on the vines at the time before they were damaged returning a higher yield than if we let Nysius vinitor visit our beans. How many starved as a result of our ploy? Who cares?
Habitat construction with enhanced and enlarged agroecosytems around the farm are the best methods or preventing and controlling outbreaks of all primary, secondary and tertiary pests.
Pesticides
We never once opted for the quick fixes found in a bottle but always relied on nature doing the work for us. In the initial stages of setting up the orchard, however it was necessary to pick up the phone, call bugs for bugs detail our experience and have them forward their recommend predatory bug. The organic way:
* Pick up the phone,
* Check the mail box,
* Sprinkle eggs on leaves in the early morning or attach paper sheets to the tree’s inner canopy,
* Walk back and have breakfast,
* Monitor bugs doing their thing.
The toxic alternative:
* Run into town to the local produce store for toxic chemicals
* Read directions and mix,
* Buy and don special protective clothing,
* Wash splashes and hands,
* Find keys and refuel tractor,
* Start tractor,
* Be careful of dangerous drifts with sprays,
* Wash down equipment,
* Pack up protective gear have a shower and have breakfast.
As can be seen from the above the biological way is quicker, safer, more effective, cost less in both monetary terms and time application and is far less stressful.
The other advantages of the organic methods are:
* No pollution of water ways,
* No need to worry about toxic drifts,
* No pollution of the ecosystem or environment,
* No dangerous flow on affects,
* No disposal of toxic waste
* No disposal of toxic or contaminated containers,
* No worry of poisoning children – In New South Wales -The total poisonings for children aged 1 to 3 has increase 160mm in the past 20 years, 89mm were where a parent was absent at the time, 1014 were from ingestion while 674 were from spillages including inhalation, 89mm happened within 1.4 meters of the ground or floor. Farm life increases both the exposure and actual reported incidents of child poisonings.
Environmental habit construction through wildlife corridors, wind breaks or riparian zones, enhancing existing natural bush areas to suit and compliment your individual operation or care for natural stands of the environment is the best holistic approach the organic farm operator or proprietor has available to them. As the farm and orchard become more self sufficient and sustainable even the low energy move of phoning for the bugs and transport for delivery are reduced dramatically.
Ants
There are 1275 species of ants presently recorded in Australia to date, with probably still around 450 species yet to be discovered. In general most ant species are not the malicious marauding felons most people make them out to be. In fact they all play an important role in maintaining a healthy soil and eco system. Most ants fit into the category of being predatory or predatory scavengers. Their tunneling operations improve soil aeration and moisture permeability.
Some ants have attracted the ideology of being farmers and some are, collecting leaf material storing it below ground to grow fungi. Other farming activities can create problems to farmers while they carry out their operations. Honeydew the liquid gold of certain ant communities, is collected; by a few species of ants, as they scurry around on the smaller stems and leaves of shrubs and trees. Collecting their rewards they viciously defend, ward off and attack any intruder which attempts to disrupt their operations including ladybirds, lacewings and parasitic wasps.
This can allow the pests usually Aphids, mealy bugs and scale insects to build up large populations unheeded by predators. The two most common species are the small black ants from Iridomyrmex rufoniger and the larger reddish coloured ants from Iridomyrmex purpurea.
Monitoring
Ants can be monitored throughout the year with most activity being during the warmer months. High levels of ant activity on the trunk is a sure sign that the trees are infested with one of numerous insect pests including aphids, pink scale, white scale, mealy bugs or herbivorous mites. A closer examination of the foliage is required to determine the exact culprit. First the trees flowers; if in flower, should be checked to see if the flow of nectar is the reason for all the activity. If this is the case no further action is required.
Most ant species especially the larger species have a preference for undisturbed bare ground with their nest mounds and trails cleared of all plant material. This has strong implications that heavy course mulches and thick cover crops will discourage those species. Our personal experience with several small to large mounds; widely scattered through the orchard, prior to mulching and sowing of the cover crops, were all active and healthy. These ant colonies had completely disappeared from the orchard area by the time the cover crops had secured a good coverage.
Control
There are 3 main lines for ant control being removal of food supplies, barriers and baits.
The most cost and labour effective approach for the control of ants is based on the control of their food source. To remove the sap sucking arthropods that produce the honeydew in which some ant species favour from the trees, pastures and cash crops will see a rapid decline in ant populations.
The sticky band methods have long been used for the control of ants. While being very effective on trees where the trunk is the only track the ants can pursue into the canopy it is time consuming and expensive to implement.
Bait with boric acid has been used to reduce ant populations in organic enterprises. Bait formulas can be modified to suit either sugar attracting or meat attracting ants. Baits should be in containers to prevent spillage resulting in soil contamination and access by non target animals. Boric acid baits are not approval for their use with some certifiers therefore approval should be granted prior to their use.
Aphids
There are four aphid species which commonly infest citrus orchards in Australia. Toxoptera citricida and Toxoptera aurantii, both known as black citrus aphid which occur in all citrus regions while Aphis gossypii the cotton or melon aphid can be found in most regions except Western Australia and Aphis spiraecola sometimes known as Aphis spiraea or apple aphid is restricted to the coastal regions south of south east Queensland and central coastal New South Wales. There are many more species which are attracted to other orchards, pastures and cash crop farms.
Aphids are more prevalent on soft new growth especially where high nitrogenous fertilizers have been used.
Monitoring
Flowers along with any flushes of new growth should be monitored along with the presence of their known predators. Parasitized aphids should also be noted.
The first batch of eggs hatch in early spring as the weather warms up. The females have wings and after they do what most of us enjoy doing to reproduce, fly to a preferred host plant to feed. 7 to 10 days later she gives birth to 40 to 60 live young which are all females. This continues until the weather begins to cool down at the end of autumn. Now for some unknown reason the last batch of young produced are both male and female. The females lay eggs which lay dormant over winter. As you can see if there is no biological control 10 aphids on your favourite tree become 400 to 600 in 7 to 10 days and by the next generation you have 16,000 to 36,000 of the little sap suckers are sucking the hell out of your garden. The next generation that comes along will produce around 2,160,000. What in the hell are you going to do?
Control
On the first site of aphids building up abnormal numbers in the early days in the orchard we immediately phoned Bugs for Bugs and bought a shipment of green lace wings. By the time they arrived within the week lady birds would be seen to ram the lesson home. The green lace wings are ferocious eaters and reproducers. After two years of purchasing the green lace wing, our orchard had reached a balance. When we first see the aphid numbers increasing we knew within a week the lady birds and Green Lace Wing would also appear in increased numbers naturally.
Lady birds lay 800 to 1,000 eggs over the 3 months of their lives and reside close to their food source of aphids or mites. The eggs hatch in 2 to 14 days. The lavae have 4 instars before they pupate. After 7 to 10 days as pupae the adults emerge. They winter beneath rocks, logs or even coarse mulch in natural bush land. It is important to have natural landscape around to maintain the balance. Ladybirds are general insect eaters having a wide variety of prey to live on including red spider Mite, white fly, leaf hoppers, leaf miner moths, small caterpillars, beetle lavae, mealy bugs and the eggs of other ladybirds like the 28 spotted ladybirds.
Green Lacewing will lay 300 to 500 eggs over the month of their lives and reside close to their food source including aphids. The eggs hatch in 3 to 6 days. The lavae have 3 instars before they pupate. After 10 to 14 days as pupae the adults emerge. They winter under rocks and logs in natural bush land. It is important to have natural landscape around to keep the balanced cycle going. Green lacewings are more fastidious eaters which prefer to eat aphids and will eat 600 to 1,000 aphids in their life time and are more mobile. They will also eat red spider Mite, white fly, leaf hoppers, leaf miners when they approach to close and small caterpillars.
Hover flies are a group of insects which often mimic wasps in size and colour. While the adults are pollen or nectar feeders the larval stage are interesting in that different specie diets vary from decomposing vegetable matter, decomposing animal matter to being insectivorous. The insectivorous species are of great benefit to humans especially in the control of aphids and leaf hoppers.
The use of chemical treatments for Aphids is totally unnecessary due to the effectiveness and cost effectiveness of biological controls.
Left Aphids your enemy https://skynursery.com/2020/07/02/natural-aphid-management/
Right Ladybeetle your ally http://www.biologicalservices.com.au/products/ladybirds-114.html
Left GreenEggs of newly hatched Lacewing, Chrysopa perla.
Right Adult Green lacewing
Photos – andi Mellis
Apple weevil
Apple weevil (Otiorhynchus cribricollis) also known as curculio beetle and cribrate weevil and Listroderes difficilis can be a major pest of many farm enterprises. Heavy infestations can defoliating complete crops and trees especially apples, pears and stone fruits. After pupating in the soil, adult weevils usually emerge during early to mid summer to begin feeding on tree foliage. During the day adult weevils shelter in crevices on the tree, under bark and in loose soil and mulches at the base of trees. At night they climb the trees and feed on the foliage of crops and native plants.
Monitoring and Control
Chewed leaf margins will indicate the presence of the weevil or beetles. Beetles are usually less active during the heat of the day and can usually be found under the leaves. To be sure of the cause, damaged trees should be inspected at night or in the early morning prior to sunrise in early twilight when the weevils are active.
Hygiene
Weevils are flightless so their spread is slow and deliberate. They are usually spread by human activity, equipment moving soil and plant material. Attention to hygiene will reduce the chance of clean orchards becoming infested. Good organic practices will reduce their numbers to where they are not a pest.
Biological control
No effective biological control agent is known however birds are natural enemies of beetles generally, and poultry like chickens, turkeys, ducks and guinea fowl have been used to manage garden weevil in Australian vineyards. While this approach has not been researched against weevils directly it would be a logical conclusion that weevils could be reduced or even eliminated from farms cost effectively with the use of poultry. In saying this I have never seen the ducks actually consume weevils in the orchard but then weevils were never a problem.
The sticky band methods have long been used for the control of ants and there is no reason why they couldn’t be used with the same results against weevils. While being very effective on trees where the trunk is the only track the weevils can pursue into the canopy it is time consuming and expensive to implement. It would be a very effective method of control if there are only a few trees affected.
Alphitonia excelsa, Tagetes sp. (Capeweed) and Rumex sp. (Dock) are all excellent small plants that can be used as a decoys. Planted in wind rows and wildlife corridors can be more easily monitored with direct action being taken there when their numbers are seen to be increasing.
Citrus butterflies
The small citrus butterfly’s caterpillars of Papilio anactus and its larger cousin Papilio aegeus can defoliate small trees with soft growth very quickly, but are generally not seen as pests. The pupae of both species over winter before emerging as adults in early spring to mate and recommence their life cycles.
Monitoring and Control
If the butterflies are observed in the orchard then monitoring is advisable especially on young trees.
Biological control
Many natural enemies including diseases, predatory bugs and parasitic wasps attack citrus butterflies. The lacewings consume the small first instar while the Trichogramma wasps are known to parasitize the eggs and young instars. Both these predators are available from biological commercial producers. As the caterpillars defoliate small trees rapidly once established the purchase and release of predators should be done at the first sighting of the butterflies in the orchard building up numbers. Larger orchards are rarely affected as the shear number of trees and the comparatively small number of butterflies is usually not worth the exercises in control.
The planting of naturally occurring host trees like Boronia umbellate or Citrus australisica in wind rows and wildlife corridors; in our experience, proved to be an affective control agent as the butterflies were more likely to be attracted to these species than orchard trees. See above for the use of decoys and sacrificial species which have proven to be very effective methods of control in the orchard.
Citrus gall wasp
Bruchophagus fellis, the citrus gall wasp is small at just 2.5mm to 2.6mm in length but can cause considerable losses of production especially amongst the various lemon varieties. Dieback in trees is severe when infestation levels are high. The female wasp of this specie lays her numerous eggs into the small developing flushes during spring. Once the larvae hatch they secrete growth regulating hormonal chemicals that interact with the chemicals in the plant which creates the abnormal growth seen and known as the gall. The gall produced, provides food for the larvae that live inside. The larvae completes its development in late winter before pupating. The adult wasp emerges from the gall in the following spring. Small holes can be seen along the galls where they have emerged. Gall wasps are most frequently encountered in central eastern Queensland and northern New South Wales coastal districts but are being encountered increasing further south to southern Victoria and the Sunraysia district probably as a result of infected nursery material being introduced to non infected areas, global warming temperatures increasing which are enough to support their life cycle and increasing wasp’s natural range.
The planting of naturally occurring host trees like Citrus australisica in wind rows and wildlife corridors; in our experience, proved to be an affective control agent as Bruchophagus fellis as they were more attractive to these species than orchard trees. We had limited success in attracting them to Pittosporum sp. though they were also infested to a much smaller degree. It is not known, whether the species on the Pittosporum species were the same specie as were on the citrus trees. A few decoy trees like the lemon eureka or Lisbon will certainly keep the villains away from your myor lemons.
Monitoring and Control
Trees should be inspected for the signs of galls in mid winter. The galls can be removed in early to mid August and destroyed by crushing or burning or examined for further action. Collect as many as feasible galls without holes from the previous season from across the orchard in late winter. Place them in a container/s marked with the various locations within the orchard and place a handkerchief over the top as a covering. Keep them indoors at temperatures near to what they would experience in the orchard or slightly warmer. The small black gall wasps Bruchophagus fellis should start emerging in weeks usually in late August in the north to early September in the south. These can be removed and killed. An effective method is to place the container in water to drown them. Two weeks later smaller deep honey coloured wasps of Megastigmus trisulcus or the larger reddish-brown parasitic wasps of Megastigmus brevivalvus may start to emerge. These parasitic wasps can be immediately rereleased back into the orchard as these are natural predators of the gall wasps.
A female Buchophagus fellis wasp inserting ovipositor during the process of laying her eggs. Chriss Freeburn.
Megastigmus brevivalvus inserting her eggs. The roughened appearance of the stem is the result of Buchophagus fellis larvae infestation. Dan papacek
http://www.doc88.com/p-078840402327.html
Biological control
The parasitic wasp of Megastigmus brevivalvus is available commercially in limited supplies only, so the above method of collecting the galls and self harvesting of the parasitic wasps with eradication locally will assist in decreasing the gall wasp and increasing the local parasitic populations. Forward ordering from “Bugs for Bugs” may guarantee supplies when they are required.
Cultural Control
Small infestations of galls must be pruned off and destroyed in early August to disrupt the breeding cycle of the wasp.
Citrus Leaf Miner
Phyllocnistis citrella is a small 2mm long by 4mm wide moth which is believed to have originated from around shanghai in China and has now spread world wide and occurs in most citrus regions across Australia. While it mainly affects citrus it has also extended its diet to include Millettia pinnata a native of Queensland and northern New South Wales. It will cause considerable damage to the north Queensland Millettia pinnata plantations once it arrives there.
It can be found all year round in the north especially on new growth flushes especially in orchards that have been heavily fertilized with high nitrogenous fertilizers. Leaf miner activity extends throughout the year in warmer locations but typically builds from the Spring flush through to the late Autumn flush. The female moth lays a single egg on new flushes of leaves where the larvae hatch and burrow into the leaf. as they feed and move along the leaf below the epidermis the typical silvery mine is formed to which gives them their common name.
Damaged leaves are distorted and become necrotic. The life cycle takes 15 days under favourable conditions to be completed. Severe infestations have been known to infect the majority of foliage on a tree or even an orchard however most damage is usually restricted to young trees less than 3 years of age.
Biological control
Most orchardists with 2 to 3 year old trees very rarely take any action; especially on organic orchards, where many native predatory and parasitic predators lurk to give reasonable protection.
There are three main control actions that can be taken for the control of citrus leaf miner. The release of several parasitic wasps and predators like the green lacewing larvae have been known to almost completely eradicate it from orchards. Toxic pesticides is the biggest single contribution to the pest building up large numbers which indicates that a predatory control agent is also wiped out at the same time. Therefore it is best to eliminate these from the orchard and to promote growth areas that support predatory arthropods.
The second method is to reduce high nitrogenous fertilizer use which causes high water and sugar flows and soft growth flushes which are susceptible to Citrus leaf minor.
The third approach involves the blanket covering of the area with a specific pheromone which sends the males into a thither disrupting mating causing the females to lay infertile eggs. The specific hormone is becoming more widely available and the cost associated with it is becoming more acceptable. The cost must be calculated to cover the three flushes a year that would be needed for complete control. One good control in Spring may be sufficient in reducing the Summer and Autumn flush outbreaks.
Fruit fly
Fruit flies are probably the worst all round pest for orchardists to combat. Fruit fly larvae damages the fruit internally, causing it to ripen prematurely before dropping to the ground. 100mm of fruit has been known to be damaged during uncontrolled infestations. Worst is the fact that the presence of fruit fly in a region can result in the loss of valuable interstate and export markets.
There are over 80 different species of fruit fly presently described in Australia while two are a major concern to orchardists:
* Queensland fruit fly (Qfly) or Bactrocera tryoni is a native species to the humid regions of north eastern Australia and now extending west into the northern parts of the Northern Territory and south into northern New South Wales. Its extensive host range includes many wild native species of fruits and many important cultivated fruits especially apples, stone fruits and citrus. The adults are capable of long distant flights which allows. This assists Qfly to remain undetected in substantially large populations in forests, bushland areas and home gardens well away from commercial orchards.
The following list includes known trees that Qfly has been found on. With such a broad spectrum of native and non native plants its eradication is a dream though control is possible.
http://www.doc88.com/p-102264312095.html
Worst may yet to come following research by Nathan Pikes & Alan Meats Volume 41, Issue 1, Pages 70 to 74, January 2002, which shows Potential for mating between Bactrocera tryoni and Bactrocera neohumeralis.
* Mediterranean fruit fly (Medfly) or Ceratitus capitata originated from northern Africa and was introduced to the south west corner of Western Australia. Unlike Qfly, Medfly prefers drier regions with less breezier conditions. Medfly infests a wide variety of fruits and vegetables. It is much less mobile than Qfly being restricted to areas close to its feed source.
Q fly and Medfly are most active from September to May or even later in the north and are dispersed into small colonies. Both species overwinter as adult flies in sheltered locations often in leaf litter or compost in riparian zones which maintains warmer conditions throughout the winter especially in cooler marginal locations. We found a cluster of flies at the base of a Bush Turkey mound just above the high water level in a riparian zone about 200 meters from the nearest tree and about 300 meters from the nearest food tree. Adults become active again as the weather warms up.
The adults can lay hundreds of eggs, in several fruits at a time, over several months, penetrating the fruits by a couple of millimetres. A female Medfly may lay up to 1000 eggs during her lifetime. Eggs hatch in a few days and the larvae eat through the fruit, growing to about 9mm long when mature. Depending on temperature, this takes 3 to 6 weeks for Qfly and 4 to 12 weeks for Medfly. Populations of fruit fly especially Q fly will continue to build up through successive generations over the spring, summer and autumn months until temperatures drop in autumn where they enter a semi hibernation state until the weather warms again.
Infested fruit ripen prematurely and drop to the ground. Mature larvae leave the fallen fruit and burrow several millimetres into the soil, compost or well decomposed mulch to pupate. Pupation depth is an important factor for growers who are considering cultivation or livestock as part of their fruit fly management strategy. Results from a range of trials indicate that pupation depth varies with soil texture and moisture content. In moist or dry sand, Medfly pupated within 30mm of the surface. In soil, several individuals were observed to burrow to a maximum depth of 75mm. When Medfly pupae were buried in compacted soil or moist loose soil, no adults emerged from deeper than 75mm, while in dry loose soil, some Medfly adults emerged successfully from as deep as 320mm. Q fly have been noted to rarely pupate deeper than 50mm in their natural habitat, with no adults emerging from pupae buried 150mm deep.
Adult female Q fly and Medfly need a source of protein energy before their eggs mature. For this, they may feed on pollen, nectar, honeydew from sap sucking insects such as scales and aphids, bird droppings or bacteria.
Monitoring and Control
Regional exclusion
A region of New South Wales, Victoria and South Australia has been designated a “Fruit Fly Exclusion Zone” (FFEZ) for the purpose of maintaining access to important markets that are sensitive to fruit fly invasion – China. The grower’s approach to managing fruit fly depends on whether they are within or outside the FFEZ.
Within the FFEZ, state agriculture departments apply quarantine restrictions, operate an intensive fruit fly monitoring program, and when necessary run eradication programs, to maintain the fruit fly free status of the zone.
Outsidethe FFEZ it is the individual landholders responsibility to minimize the risk of damage to their crops and neighbours.
With everything you hear about Fruit Fly the best I can do is offer 2 solutions. With citrus avoid the species or varieties that are susceptible. In our orchard we had the early Clementine which was very susceptible to attack in the district yet we had very little damage. Maybe a couple of dozen fruits off 40 trees in a season. The fruit fly larvae are most susceptible when the fruit hits the ground and they leave the fruit to crystallize and pupate beneath the soil surface. This is when the ducks eagerness in devouring fallen fruit came in handy. This affectively broke the fruit flies breeding cycle on our property. By diverting livestock so that they fed beneath the trees that are susceptible to fly in the first place will ensure a maximum number of fallen fruit are consumed as they ripen. Whether our control was from the ducks cleaning up fallen fruit quickly or from another natural predator has never been researched and is still unknown. Maybe it was a combination of many organic controls coming together.
The second control method is to grow out of season citrus or fruits that mature in late winter or fruits that naturally have thick skins which deters the females from depositing their eggs. There are some indications that the larvae can be killed by citrus oils in the rind of immature fruit.
Damage fruits from hail or splitting; from incorrect watering or fertilizing regimes, or when there are no other suitable fruits available appear to be more likely to be used for reproduction. On the last point decoy or sacrificial trees may also help to maintain control. Here the fruit of a more conducive tree can be used where ducks or pigs are housed to great affect consuming the more desirable fruits like apples, pear, stone fruit or loquats and leaving the productive trees alone.
If a loquat tree is used then an inverted umbrella made of fine shade cloth can be used to harvest the fallen fruits with the maggots. As the maggots leave the fruits they will accumulate at the base of the funnel and dehydrate. We tried this method which was time consuming to set up but was very successful and ended up attracting a yellow faced honeyeater into the centre which fed continuously day after day on maggots and fruit. Maggots are considered a delicacy so this may open up a whole new industry for some entrepreneurial young farmer.
Some districts apply wide suppression of fruit fly management by having growers cooperate in large scale bait sprays, mating disruption with pheromones, and mass release of sterile male flies. It is recommended that organic growers actively participate in these programs, provided the methods used on their properties are acceptable to their certifying organization.
Traps are generally used for monitoring fruit fly numbers rather than
suppressing their numbers. Populations of the Bactrocera sp. of fruit fly in olives orchards have been reduced by mass trapping programs. This approach may have some merit using a combination of traps which attract fruit flies with pheromones, food scents or visual cues. Pheromone traps attracts male fruit flies to liquids where they drown, food lures or wet traps where the traps contain an aromatic liquid food to attract fruit flies.
The acidity of the food used appears to be critical as fruit flies seem to prefer higher pH fruits around 9 and are less attracted as the lure becomes more acidic. Traps need to allow the flies easy entry while excluding rain or irrigation water. Clear plastic bottles with several 1cm diameter holes are one option. The food luring traps are best placed from 1.5 to 2 metres above the ground in areas where fruit flies rest or feed. This is usually in shadier positions in the trees within the trees being protected. They should be placed every 4 to 5 metres apart for best results. Broughton S (2004) Control of Mediterranean fruit fly (Medfly) in backyards. Department of Agriculture Western Australia, Report Gardennote 24. http://www.agric.wa.gov.
au/content/pw/ins/pp/hort/gn2004_024.pdf
An alternative trapping approach uses fruit mimics – coloured spheres
coated with a sticky gel like TacGel or Tangle foot. Australian research indicates that blue or white for spheres appear to be the best colours for attracting Qfly and yellow for Medfly. Drew RAI, Prokopy RJ, Romig MC (2003) Attraction of fruit flies of the genus Bactrocera to colored mimics of host fruit. Entomologia Experimentalis et Applicata 107, Pages 39 to 45.
It seems that larger spheres around 100mm diameter are more effective than smaller ones. Because the visual range of fruit flies is about 6 meters, coloured traps should be placed within 6 meters of the trees being protected. A disadvantage of sticky traps is that the gel becomes less sticky with age, especially in dusty conditions.
Bait sprays are based on an attractant and spinosad to kill the fruit fly once it has been attracted to the bait.
All the above baits, traps and lures are generally effective when they cover the whole area but are relatively expensive and labour intensive to place in each tree.
Post harvest management Fruit treatment
There are currently no organically acceptable post-harvest dips registered for use against fruit fly on fruit in Australia. The only acceptable postharvest treatment is cold disinfestations where the fruit is subjected to temperatures between 2 and 4 degrees for 72 hours where fruit is exported. The ideal temperature for killing fruit fly is 2.7degrees centigrade.
Fruit inspection
In fruit fly areas, the chance of identifying stung fruit and excluding them from packing may be increased by storing the fruit for a few days after harvest. This time allows the sting to become more obvious and so more easily detected. In some situations, untreated organic citrus from fruit fly infested areas can be shipped within or between states if it is inspected, packed and transported according to strict protocols. The protocols may also require that a baiting and trapping program is in place. Because such protocols can vary from state to state, growers should refer to their state agriculture departments for details.
Light Brown Apple Moth LBMA (Epiphyas postvittana)
Epiphyas postvittana is another leaf roller moth native to Australia. It has a very wide range of hosts including manynative and introduced weeds, crops and ornamental plants. It has been recorded on 800 native trees, shrubs broad leaf weeds with the exception of grasses and now an additional 250 exotic fruits, vegetable and ornamental species like Roses and Chrysanthemum species have been included in its diet including northern hemisphere pine trees. This gives it a name that could make it one of the worst moth species in the world for being invasive.
The caterpillar and adult stage of Epiphyas postvittana. http://lepidoptera.butterflyhouse.com.au/tort/postvittana.html
It produces 3 or 4 generations each year with peaks in egg hatch typically occurring in winter, spring, early to mid summer with the fourth during late summer or early autumn in warmer districts. Each female moth will lay between 120 and 500 eggs in her lifetime which take between 5 and 28 days to hatch depending on the temperature. The caterpillars of LBAM are relatively aggressive in apples, stone fruit with more occurrences being reported amongst Avocado and Citrus growers because:
* They damage flowers and fruits at the fruit set stage, causing fruit to abort,
* They chew the rind of small fruits under the calyx, resulting in a halo scar when the fruits grow making them unacceptable to the market,
* They burrow under the calyx or tunnel into mature fruit where they become a quarantine issue for some export markets.
LBAM activity is easily monitored with pheromone or port wine traps and tree inspections. Careful monitoring is used to determine the exact time of spraying to coincided just after egg hatching, the level of parasitism in the species, with the most effective time for and quantity of parasites to be released and the level of LBAM infestation of the crop by caterpillars. Pheromone traps are available commercially are relatively expensive but have the benefit of being LBAM moth specific. Moths that enter the trap get caught on a sticky card and can be counted easily.
Home made port wine traps can be made from any suitable container which are about 150mm in diameter and 200mm deep. The container is partly filled with a solution of 10 to 15mm percent port wine. The rest can be consumed for medicinal benefits – Stress related relief from having to confront and control LBAM. A cap of shade cloth with at least 10mm holes will help exclude birds, preying mantids and other larger animals from the trap. Unfortunately port wine traps attract a wide range of insects including other small moths and neighbours who want to try the product before they use it so have plenty of port on hand. You may need to test several brands of port to see which is the most affective.
The producer needs to be able to identify LBAM correctly. It is best to check the traps every three days and monitor the numbers on a graph and to allow freshly paralytic but happy, caught moths to be counted more easily. Any sudden increase in moth numbers over a couple of weeks indicates a rise in moth flight activity, mating and egg laying is imminent. 10 to 12 days later may see a corresponding increase in egg hatch and larvae activity, which may indicate the best time to apply a biological control.Note there is not necessarily an accurate association between moth numbers and the subsequent population levels of LBAM on trees as many moth eggs can be already parasitized. This is why peak periods in moth activity should stimulate more interest in more detailed inspection of trees rather than reaching for sprays or telephones for ordering parasitic organisms. These tree inspections involve looking at:
* Young leaves, flowers and fruits that are webbed together,
* More mature fruit that are touching other fruit or leaves looking for bore holes,
* Checking carefully under the calyx of all flowers and or fruits in a systematic manner in the orchard or on the farm for holes or other tell tale signs.
LBAM egg masses are difficult to detect, but any unrecognizable fresh egg masses that are found can be circled using a permanent marker, and the twig tagged with coloured tape or collected for monitoring inside the house or farm shed. These marked egg masses may then be monitored easily to determine their hatching date and rate of parasitism. If parasitized they can be transferred back to the farm.
Biological control
LBAM eggs and larvae are preyed upon by numerous predators including spiders, green lacewing larvae, predatory shield bugs and some earwig species. Trichogramma sp. of wasps parasitize LBAM eggs while other parasitic wasps and hover flies attack the larvae. The harbouring of beneficial species around the farm are important sources for controlling LBAM. Some predators, including Mallada signata the green lacewing and species of Trichogramma sp. for control are commercially reared by Australian insectaries for control.
A healthy inter row of nectar and pollen producing grasses and legumes as alternative food sources is necessary for Trichogramma carverae and Mallada signata to promote their longevity and continuous life cycles on the farm.
Trichogramma carverae is available in convenient perforated cards each containing 1000 parasitized moth eggs. These cards can be easily placed amongst the trees spread in a grid format for best control. As the wasps mature, they emerge through the perforations and begin their search for more LBAM eggs to parasitize. By distributing Trichogramma cards during the peak period of LBAM flight activity, the wasps should be emerging when fresh LBAM eggs are present.
A synthetic version of the LBAM sex pheromone is available in twisttie type ties that can be wrapped around small branches. The ties release their contents disrupting the males attraction to the females.
A strong limitation of this control is if previously mated females enter the treated area from nearby untreated areas in wildlife corridors or wind rows makes the need for treating these areas a must at the same time.
Biological insecticidal sprays based on Bacillus thuringiensis (B.t.) and spinosad can be used to manage LBAM. Because B.t. sprays selectively kill caterpillars without harming beneficial parasites and predators but are non selective on most caterpillars, They can be used to control LBAM without disrupting the biological agrobiological system directly but will interrupt the predatory chain by creating a vacuum in the immediate food chain. This is far less disruptive than broad spectrum sprays in conventional farming tactics. B.t. sprays have a very short residual life so spray timing is critical if good results are to be achieved. Both insecticides will have greatest effect if applied when most LBAM larvae are very young. At this stage, the caterpillars are very small, exposed and most easily controlled. After a relatively short period, the caterpillars start to produce webbing to make sheltered feeding sites. Once they are wrapped in these webs they are much more difficult to control with sprays.
Cultural Management
Removal, limiting the growing of broadleaf weeds like Capeweed and Dock to more easily controlled locations in wildlife corridors and wind rows is recommended. As LBAM has a very large host range, encompassing over a 1000 species of plants from trees to clover it is impossible to remove all external feed sources. It has not been recorded feeding on monocotyledons or grain crops. In fact diversity in cover crops and in corridors could be part of the secret in supporting a wide range of predators which naturally keep it under control. This may have aided our ability to keep this potentially damaging pest at bay. We had recorded it on a number of occasions throughout the orchard but it never gained pest proportions and was always limited to a few native plants or the clover mainly on the margin of the orchard. The worst outbreaks were recorded amongst the various poppies we grew for seed. But not to the point we lost production or wanted to restrict its numbers.
Mealybugs
Mealy bugs are in the familyPseudococcidae and is one group of pests that many chemical farmers report having annual run ins with while the well maintained established organic producers have to hunt them down to make a recording. The mealy bugs or woolly aphids are very variable and require very variable species in the inter rows for control. The greater the diversity the fewer experiences you have as the diversity will include parasitic wasps, predatory hover flies, ladybirds and lacewing larvae.
Broad spectrum pesticides along with target sprays are the friend of mealy bugs as they curb the number and variety of predators in the field and allow its numbers to increase to a point where they are noticed or damaging.
Some biological controls include the black or deep brown mealy bug ladybird Cryptolaemus montrouzieri. A small ladybird with a big name and just as big a reputation for eating Epiphyas postvittana. With the green lacewing Mallada signata and Leptomastix sp. of wasp are all commercially available for dinning on mealy bug.
Where mealy bugs and ant infestations coexist, Cryptolaemus montrouzieri’s larvae are the mealy bug look-a-likes which is great for partying with ants and mealy bugs before devouring their herd on your favourite tree or flower.
Thrips
Thrips and strawberries, roses or gladioli are usually spoken in the one sentence with the next being Frankliniella occidentalis This thrips is gaining a reputation in Australia for getting around. Getting around the countryside, getting around more varieties of plants which now include stone fruit and many ornamentals and getting around toxic chemical sprays. There are presently 36 Thips species in Australia that have the potential to damage or destroy whole crops.
The following Thrips have now been found in Australia Anaphothrips obscurus, Anaphothrips sudanensis, Caliothrips fasciatus (Though recorded from Australia it is native to California in America. All the specimens to date collected are dead. This is probably as a result of species entering the country have been in the naval of naval oranges that have travelled under refrigeration at 2.78 degrees Centigrade for 24 to 28 days.), Chaetanaphothrips leeuweni, Chaetanaphothrips orchidii, Chaetanaphothrips signipennis, Dichromothrips corbetti, Frankliniella occidentalis, Frankliniella schultzei, Frankliniella williamsi, Helionothrips errans, Heliothrips haemorrhoidalis, Hercinothrips bicinctus, Hercinothrips femoralis, Limothrips cerealium, Megalurothrips usitatus, Microcephalothrips abdominalis, Neohydatothrips samayunkur, Pseudodendrothrips mori, Leucothrips nigripennis, Odontothripiella australis, Parthenothrips dracaenae, Pezothrips kellyanus, Scirtothrips aurantii, Scirtothrips dorsalis Selenothrips rubrocinctus, Stenchaetothrips biformis, Thrips florum, Thrips hawaiiensis, Thrips imaginis, Thrips nigropilosus, Thrips novocaledonensis, Thrips palmi, Thrips parvispinus, Thrips simplex & Thrips tabaci.
Female Thrips lay between 25 and 50 up to 150 large reniform eggs in slits she makes between the tissues of leaves or other soft parts on a plant. The eggs take 2 to 5 days to hatch depending on the weather. The whole life cycle can be as short as 14 days depending on the weather and species. It is this turn around that makes Thrips so devastating with their size and that they can be transported easily by wind currents around the property. Without predation a single Thrips can increase her offspring to over 15,500,000 in just 3 months with the rest of the year still ahead of her and her off spring. This rate of propagation also gives the Thips an advantage when chemicals are used as if the whole population is not knocked down or a couple of Thrips become resistant to the chemical then total resistance evolves rather quickly.
Thrips feed by puncturing the epidermis and sucking out the cells. This leaves the typical finely speckled necrotic appearance against a background of dull green of the plant material or dull colouration of the fruits or flowers. Many thrips suck the cells of buds and fruits before fruit set causing the plants to abort or the buds do not proceed towards flowering. Thips infestations usually require several treatments of toxic systemic chemicals of different types to have any effect.
Biological Control
Biological control is difficult even under ideal conditions for the predatory mites as Thrips can out breed the mites every time. The use of spinosad with a variety of more resistant predatory Mites has proven effective in controlling Thrips but not eradicating them.
Thrips have numerous natural enemies including parasitic wasps,
predatory thrips, predatory mites and predatory bugs, and fungal diseases which are more prevalent in humid locations. A study in South Australia’s Riverland district found lower Thrips populations to be linked with higher numbers and species diversity of soil dwelling predatory mites. Baker G, et al. (2005) The biological control of Kelly’s citrus thrips in Australian citrus orchards by soil predatory mites. In ‘15th IFOAM Organic World Conference ‘Shaping Sustainable Systems’’. Adelaide, South Australia. (International Federation of Organic Agriculture Movements).
Chapter 33f
Cultural Management
One of the best methods of control used by cash crop producers is to change the crop if possible as soon as the Thrips numbers start to increase. The destruction of plant material by burning has only minimal impact, as Thrips are usually in the soil, and on neighbouring vegetation including wind rows, wildlife corridors and natural bush.
Ongoing research is investigating the value of soil management to improve biological control of thrips. There appears to be a direct correlation of predatory mite numbers and higher soil carbon levels and a greater prevalence of grasses and cover crop variety in the inter rows of orchards.
Associated research conducted by Colloff MJ, Fokstuen G, Boland T (2003) ‘Toward the triple bottom line in sustainable horticulture: Biodiversity, ecosystem services and an environmental management system for citrus orchards in the Riverland of South Australia.’ (CSIRO Entomology: Canberra).
http://www.ecosystemservicesproject.org/html/publications/docs/soil_final_report.pdf found the following characteristics to be common across orchards with and without significant thrips problems.
Orchards with thrips problems tended to have:
* Inter rows of bare soil or occupied by annual weeds or a mono cultural ground cover,
* Low densities of predatory mites equal to 520 per sq meter average annual populations of predatory soil mites,
* Low levels of carbon present in the soil,
* The prevalence of toxic chemicals in use on the farms.
Orchards without thrips problems tended to have:
* Dense, diverse inter row of swards of perennial grasses and herbs,
* High densities of predatory mites equal to 4147 per square meter average annual populations of predatory soil mites,
* High levels of carbon present in the soil,
* The lack of toxic chemical pesticides and herbicides on the farms.
This research certainly indicates that the suppression of thrips can be maintained by:
* Maintaining a diverse ground cover which includes grasses for pollen production and legumes for soil fertility,
* Improving soil organic carbon levels through addition of compost, mulching or growth of organic matter,
* Adding organic mulch to maintain favourable soil conditions for predators and parasites and increase organic carbon levels,
* Resist the temptation to use any chemicals on the farms.
New Zealand researchers found that 100mm of mulch comprising of about 75mm woody material and 20mm fines and or green material applied within the drip line of lemon trees doubled the number of predatory mites in the soil after just four months. The mulch significantly reduced numbers of KC Thrips adults emerging from the soil after pupation, but whether this was due to higher levels of predation or to a physical effect of the mulch or both was not determined. El-Banhawy EM, et al. (1997) Interactions of soil predacious mites and citrus nematodes (parasitic and saprophytic), in citrus orchard under different regime of fertilizers. Effect on the population densities and citrus yield. Journal of Pest Science 70(1), Pages 20 to 23.
Greenhouse Thrips populations are known to increase with excess nitrogen levels in some crops therefore it is reasonable to assume that the same occurs in the field. The above 2 researchers also found that there is a significant increase in predatory mite activity and numbers where carbon levels have increased in the soil or are substantially higher 520 predatory mites in a square meter average in low carbon soils compared to 4147 predatory mites in a square meter average in high carbon soils.
Pesticides
While insecticidal potassium soap (greenhouse thrips), Pyrethrum extract, vegetable oils and other organic insecticides are acceptable registered inputs for thrips organic producers generally shy away from them due to the highly disruptive nature of the products against predators in favour of controls that encourage greater biological activity in the soil and on the crops themselves.
Mites
Mites are generally a serious pest of which there are numerous species in Australia that cause damage to leaves, flowers and fruit. The main mites causing minor to major problems in different crops around Australia are:
* Brown citrus rust mite (Tegolophus australis)
* Citrus rust mite (Phyllocoptruta oleivora)
* Citrus bud mite (Aceria sheldoni)
* Broad mite (Polyphagotarsonemus latus)
* Two-spotted mite (Tetranychus urticae)
* Oriental spider mite (Eutetranychus orientalis)
* Red legged Mite (Halotydeus destructor)
* Balaustium medicagoense
* Bryobia sp.
* Citrus red mite (Panonychus citri)
* Citrus flat mite (Brevipalpus lewisi)
The latter two are usually only minor pests while Balaustium medicagoense andBryobia sp. at the present time appear that they may become more destructive in grains and pasture areas than Halotydeus destructor. Evolving management practices along with global warming are believed to be contributing to the changing patterns of mite sp. and Mite and Thrips occurrences and destructiveness being experienced within the grain industry in Australia and probably else where. And if that is not enough to pull your hair out then there is the fact that most mites are predatory in habit and have to be identified with programs to suit them as well.
When herbivorous sucking mites feed it is usually in congregations as the bruising created by one mite feeding assists its neighbour to gain access easier. This results in discoloured surface scarring on fruits appearing very quickly on infested plants. The exception is the citrus bud mite that causes distortion of fruit, leaves and shoots. Most species prefer warm humid conditions and can multiply rapidly with up to 30 generations per year especially in the more humid coastal districts however 4 to 6 generations a year is the norm. Problems are further accentuated as the eggs of many species are diapause meaning that they have the ability to remain in a dormant state for many months until conditions are unsatisfactory and will not develop further until the conditions again become more favourable.
An important fact in the control of mites organically is the preservation of wildlife corridors coupled with good inter row cover crops with a wide variation of grasses, legumes and annuals. This is vital in supporting a wide variety of natural predators.
Avoid broad spectrum pesticides is a must, to preserving predatory mites and other predators within the orchard and adjacent land. The preservation of predator habitat can be achieved by simply altering the slashing program so that the orchard’s inter rows always contain flowering grasses like Rhodes grass, annual and perennial rye grasses with other grasses and annuals which are valuable pollen source for many predatory mites and other predators. Smith D, Papacek D (1991) Studies of the predatory mite Amblyseius victoriensis (Acarina: Phytoseiidae) in citrus orchards in south east Queensland: control of Tegolophus australis and Phyllocoptruta oleivora (Acarina: Eriophyidae), effect of pesticides, alternative host plants and augmentative release. Experimental & Applied Acarology 12, Pages 195 to 217.
Californian experiences indicate that dusty conditions worsen the infestations of certain mites. Therefore dust mitigation would be a worthwhile incorporating into a management plan in orchards and is consequently included in recommendations for insect and mite management. This mitigation is not a concern in organic orchards where good inter row cover crops which include Rhodes grass and annual and perennial rye grass are a normal part of the management plan. Further citrus that are water stressed appear to be more susceptible to infestation by some mites than adjacent orchards where good irrigation regimes are in place. This probably applies to most other fruit trees at the same time. Flint ML (2006) ‘UC IPM Pest Management Guidelines: Citrus.’ (IPM Education and Publications, UC Statewide IPM Program, University of California.: Davis). http://www. ipm.ucdavis.edu/PDF/PMG/pmgcitrus.pdf
The following recipe I came across years ago needs to be checked for effectiveness. Here is an opportunity for a member to do a little experimenting and get back. Predatory damage could also be investigated at the same time.
1/4 cup Baking Soda
1/2 cup Apple Cider vinegar
1 Tablespoon Lemon Juice
2 drops dish detergent
1/4 Teaspoon Epsom Salts
Take a cup of very hot water and desolve the epsom salts, take rest of ingredients and place in a clean 2 liter bottle and let work out. Add epsom solution. Add water to fill to 48ozs(3/4 full). Shake well.
Spined citrus bug (SCB) Biprorulus bibax &
Nysius vinitor (Rutherglen Bug)
These two shield bugs are particularly damaging to crops on the east coast. Both can be found in increasing numbers at distances of up to 500 meters from the crops in Eucalyptus forests and Fabales species making control at the source impossible. They causes drying and discolouring of shoots and fruit segments.
SCB prefers lemons and mandarins but will also feed on oranges while Nysius vinitor likes to devastate my climbing beans annually just after New Year.
SCB eggs are usually laid in rafts from mid spring to mid autumn. The nymphs of SCB can usually be found all year except late winter to early spring in regions that have moderate to severe frosts. In early autumn, SCB adults migrate from lemon trees to the nearest non lemon citrus trees where they spend winter. Around 60mm to 80mm of the population gather on the adjacent rows to lemon trees, sometimes gathering in groups of several hundred but usually from 5 to 30 in a cluster. The grouping is in response to an aggregation pheromone produced by the males. This is an ideal time for eradication minimizing the population that is able to breed the following spring.
Monitor
Population levels of adults and eggs should be checked regularly from late spring to early autumn. Eggs can be found on the underside of leaves in yellowish coloured egg rafts. Eggs with black dots are probably parasitized. There are at least 7 different parasitic species in Australia that parasitize the eggs.
Biological control
Parasitism levels should be noted and if possible the parasite identified. James D Yanco Agricultural Institute, N.S.W. Agriculture & Fisheries, Yanco, N.S.W. 2003 found that of a total of 726 eggs collected from citrus orchards near Cudgel and Leeton in southern western New South Wales Trissolcus biproruli, Acroclisoides tectacorisi and Anastatus biporuli had parasitized 16mm of the eggs. The highest parasitizing occurred in late December.
Cultural management is problematic as seen above, where lemons are a small proportion of the orchard they will be attracted to the lemons over other types of citrus. It may be beneficial to remove the lemon trees and any individual mandarins that the trees collaborate in. This will reduce the orchard’s overall alluring appeal for SCB. Coupled with several lemon trees planted outside the orchard with a single mandarin tree next to them as decoys or sacrificial trees could be another worthwhile strategy. Decoy trees offer the producer the chance to have the bugs in one area for easier management.
According to research conducted by Biological and Chemical Research Institute, Department of Agriculture, Rydalmere, N.S.W on laboratory observations of material collected from wild populations near Leeton, Bathurst, Yanco, Dareton, Rydalmere & Cootamundra confirmed the parasitic nature of Alophora lepidofera on Nysius vinitor and Nysius clevelandensis. The incidence of parasitism in the field collected samples of the two species in 1971 ranged from:
* 10 mm to 61.7mm on Nysius vinitor for females and from 0mm to 4mm for males.
* 13mm to 60.9mm on Nysius clevelandensis for females and from 0mm to 5mm for males.
The collections were made from various species of the Asteracea family, Pisum sativum and Poa annua.
This collection points to the need to again have diversity in the inter rows of orchards and along wind breaks and wildlife corridors to feed and maintain good health of predators. More work needs to be done on the affects, breeding and use of Alophora lepidofera as a control agent for the control of Nysius vinitor and Nysius clevelandensis .
It also indicates with such a large male female discrepancy if accurate (assuming that this is the normal ratio of males to females in natural populations) during the breeding season that the breeding and releasing of sterile males would have a great impact on the species as a whole.
Snails & Slugs
Several species of snails cause problems on Australian rural enterprises. The common garden snail Helix aspersa can cause considerable damage by eating the bark from young trunks and twigs and chewing on the rind and skins of citrus and other fruits and vegetable crops. The small brown snail Microxeromagna armillata creates major quarantine issues for export markets when they have been detected on fruit, cartons, pallets or in shipping containers.
During autumn and winter, mature snails which are hermaphrodites get together usually on a monthly basis for a love in. The courtships last for anything from a couple of hours to a day and can involve intricate courtships. They then part and lay 20 to 100 eggs into the top few centimetres of moist soil. This means under ideal conditions our humble snail could number over 10,000 million in just 6 months. Fortunately though many are eaten by predators, many are washed away and of those that do hatch, it is best to be first out as the baby snails will dine on their siblings for their first hearty meal. Let’s face it of us too enjoy escargot natural.
Baby snails will take up to one year to mature and start egg laying with some under ideal conditions being known to reproduce in just 3 months. Snails are most active in moist, mild to cool conditions. Snails and slugs especially snails won’t be a problem on strongly acid soils.
Notate that most Australian slugs are not detrimental and in fact consume fungi hypha and well decomposed matter.
If Helix aspersa are plentiful and no one in the neighbourhood is poisoning them then here is your chance for real organic French or Italian cuisine. Place the culprits in an enclosed container and feed them flour. Snails are particularly fond of cornmeal and are soon transformed magically from garden pests to “Escargot Deliciousus.” Sort of like “Killing 2 birds with the one stone.”
Biological control
Although snails have many natural enemies including birds, rats, mice, lizards, beetles and predatory snails, biological control alone is usually not sufficient to prevent snail populations from building up in some situations especially in warm humid Autumns that extend into Winter.
Cultural management techniques include weed management and barriers to snail movements up the trees. Pruning to keep all foliage and fruit off the ground reduces the opportunity for snails to enter the tree canopy from drip lines. Placing bands around the trunks of trees or the construction of physical barriers around vegetable and flower plots will also keep them out. These methods are costly and highly labour consuming to construct and maintain.
Cultivation destroys snails and their eggs, and exposes others to predation by natural enemies including birds and lizards. It is a cheap way to form a barrier around vegetable and flower beds. Weed control also reduces the snails’ food source and shelter especially in the absence of crops or ducks.
Other methods of applying simple snail and slug barriers is to include dry and/or coarse materials such as rock dust, sawdust or wood shavings, ash, diatomaceous earth and lime. These materials can be applied around the base of trees and work by interfering with the snail’s ability to lay down a slime trail as it moves. However, they are still rather labour intensive to apply and maintain. They also only work when weather conditions are dry or where drip irrigation is used.
Copper in various forms has a strong repellent effect against snails as a chemical reaction occurs with the snail’s slime and it has a drying affect. Copper tape or copper foil is available commercially and can be wrapped around the trunk of trees as a snail barrier. However, like the other barriers mentioned is labour intensive as well as expensive to apply. Irrigation type and timing may influence snail activity in low rainfall districts.
Irrigating over night has the treamendous advantages of reducing
evaporation, but it does encourage snails and slugs by maintaining moisture over a large area and also maintaining more even temperatures. That is the temperatures are reduced on hot summer days to the snail and slugs satisfaction and increases evening temperatures on cold frosty nights again to the snail and slugs satisfaction.
Hygiene
Snails prefer moist cool areas to rest and breed so accumulated piles of plant prunings, mulches and lush, dense variable inter row growth are all favoured. The exact conditions orchardists seek for their trees and vegetable and flower growers accumulate prior to composting. Removal of these situations from within and around the organic orchard are not practical so these should be considered when designing the orchard or farm.
Control
Snails and slugs have a particular fondness for fresh vegetables and in particular fresh fruit especially citrus. They have a very good sense of smell and have been recorded covering 480 meters in a single night or 800 millimeters a minute flat out.
If it is practical ducks are fantastic for the control of snails and slugs. A small duck on an average to large building block will see the yard free of the pests in a very short time. The benefit here is the eggs will have thick shells and take on a deep orange yoke with good flavour. The down side is the ducks will eat everything they can get their little beaks around. Caterpillars, beetles, scraps and your vegetables will also be consumed so be aware if you want them.
Orchardists have the distinct advantage when it comes to snails and slugs in that they can turn to ducks. Khaki Campbell and Indian Runner ducks are preferred and have earned themselves the name; and rightfully so, as being the most efficient snail hunters in the world as they are active friendly breeds. Stocking rates of eight to 10 ducks per hectare have been suggested as sufficient for snail control even in heavily infested areas. Little wonder we had no problems with 400 pairs of legs and beaks on snail duty daily in the orchard.
Beer is another good attractant. Place a saucer of beer and vinegar out in various locations around the garden and partially cover it with a roof. This way the pests will be happy to stay put even during the day. The following morning it is a matter of lifting, collecting and squashing or purging for the table.
Orange peels covered over with a small dark coloured roof will attract the pests for several days and keep them there. Again like the beer, the following morning it is a matter of lifting collecting and squashing or purging for the table.
Commercial snail baits that are approved for use on organic enterprises can be applied around the base of affected trees or broadcast across areas that are directly affecter by the Gastrpods.
Baits are most effective if applied just before rainfall or irrigation which will stimulate snail activity. Snail populations are already reduced by natural predators so baiting is best carried out in Autumn before the autumn or winter rains start and egg laying most likely has not commenced. It is not known to the author whether the baits are toxic to predatory snails that may consume a baited herbivore.
Diseases
Plant disease like human differ from most pests and weeds in that they are more difficult to control once established. With ideal conditions and soft weakened plants, diseases can spread quickly damaging crops, severely hampering maximum growth in fruit, seed or leaf production or at other times disfiguring or making the colour unacceptable for sale. In the case of disease the old saying of prevention is better than cure rings true. In reality, disease eradication is rare and adequate suppression is what is desirable. The level of intervention required to maintain this situation can be minimized by designing and managing the farm ecosystem to reduce the crops susceptibility to known diseases in the area. Disease control or suppression is really all about the full integration of weed suppression and in particular vector pest suppression in the wildlife corridors. A strong commitment to correct identification of vector pests in the district allows for the correct decoy and attractant plants to be nurtured so that surveillance and monitoring can be easily and regularly maintained. For all producers, these outcomes include:
* The reduction of environmental impact and the fostering of a large sustainable variation of predators of known and possible vector herbivores in the wildlife corridors,
* The reduction or elimination of all toxic and even non targeted chemical residues on the farm,
* The lower risk to personal health through unavoidable inhalation and direct contact of synthetic often systemic pesticides,
* A greater understanding of the orchard ecosystem provides a more
pleasant, personal interest in what is happening which leads to greater satisfaction and ultimately greater job security on the farm.
Overall the cost effectiveness of wild life corridors often exceeds that of the costs of the additional loss of land to production and health issues which are generally not evident in the short term. This integrated approach is particularly valuable because of the restricted range of agricultural inputs permitted under organic standards. Once the farm has been totally integrated into the surrounding forest, bushland, plains or waterway weeds, pests and diseases are far less likely to occur. Citrus producers would be advised to obtain a copy of Smith D, Beattie GAC, Broadley R (1997) ‘Citrus pests and their natural enemies: Integrated Pest Management in Australia.’ (Queensland Department of Primary Industries and Horticultural Research and Development Corporation: Brisbane) while hoticulturalists and agricultural producers would be advised to obtain a copy of Dufour R (2001) Biointensive integrated pest management (IPM). National Centre for Appropriate Technology, Fayetteville, Arizona, USA, http://attra.ncat.org/attra-pub/ PDF/ipm.pdf.
Quarantine & Hygiene
Prevention is better than cure and is certainly far more cost effective. Quarantine and hygiene are the best defenses against the introduction and spread of unwanted species. They are also cost effective when compared with long term eradication or suppression of some pests, weeds and diseases. Simple techniques like restricting vehicle access and plant or soil movements onto the farm or orchard. Equipment wash down after off site use. Using clean, accredited propagation material or seeds and destroying by burning any disease infected plant or animal material where necessary, can help avoid weeds, diseases and pests before they become evident or prevalent. I have personally ordered council spray operators off the property (nature strip) because of possible drift and soil contamination. Herbicide control officers as they like to be known in our area are totally convinced that there is no other way than to drench the whole country side indiscriminately with toxins. It took us nearly 10 years to convince our council that we were not aggressive anti establishment that wanted to cause trouble and to prove that our way does work but we need the exclusion of all toxic products not just a selected few.
Wind Reduction:
Wind either aids or inhibits the movement of many arthropods, viruses, fungal spores and is certainly critical in spray drift from adjoining properties. It is therefore highly beneficial if possible to create wind breaks that take into account seasonal movements of pests, weeds seeds and fungal growths. Exposure to cold conditions, usually worsened by cold breezes, increases the susceptibility of many plants to certain diseases. Conversely the same is true of plants that suffer hot drying winds for prolonged periods or the drying affect of dry westerly winds along the east coast. Many fruits are subject to wind induced rubbing blemish which can be eliminated with properly created wind breaks that serve a duel purpose as a wind break and wildlife corridor.
Dust Minimisation:
Dusty conditions reduce the effectiveness of some predatory beneficial species. Ladybirds and parasitic wasps have been known to decline in numbers along gravel roads or headlands where white scale and pink scale infestations are heavier and gradually disappear as they move to the inner sanctums or orchards or crops. Dust has also been linked to increased mite problems in orchard studies overseas. Further photosynthesis is reduced causing a decline in fruit production, declines in root crops adjacent to the outer rows and reduction in leaf quality and vigor of leafy vegetables.
Therefore dust management on the whole is a worthwhile adjunct with wind breaks when creating a wildlife corridor. Minimizing farm traffic in vulnerable locations is also affective. The application of old engine oil, left over oil spray or similar materials to the tracks paths and roads to settle the dust while worthwhile is not acceptable under organic standards.
Irrigation type:
The type of irrigation system can influence pest, disease, fungal outbreaks and weed growth. Different sprinkler types create different microclimates and humidity throughout the enterprise. Humidity can be increased in enclosed locations which are more likely to cause fungal out breaks. Overhead sprinkler systems may wash the foliage clean of dust, honeydew and black sooty mould while creating better conditions in the inter rows for green manure crops and green mulches. Overhead sprinklers are also very affective in reducing frost damage which has the added benefit of adding extra moisture to the soil from the frosts. The unfortunate part this is when the trees and many crops use less water and growth is at a minimum especially amongst many of the fruit trees.
Under tree sprinklers can support ground cover establishment closer to the trees while reducing soil splash but do not wash foliage clean or remove honey dew and black sooty mould. Drip irrigation helps to minimize weed growth, does not wash foliage and limits the potential for establishing ground covers and other beneficial plants including ‘insectariums’ for the healthy growth of predatory arthropods. Drip lines offer wet and dry zones throughout an orchard creating stress zones outside the immediate drip range. Under tree micro jets were used to trap additional moisture by creating eddies inside our orchard during dense fogs in late winter, spring and early winter in Nana Glen. Here they were responsible for adding up to 40 litres a tree an evening when in use under optimum conditions during dense fogs.
Orchard or Plantation Nutrition
Excessive nutrients supplied, especially in the form of high NPK fertilizers leads to soft growth that is more susceptible to insect attack as the soft growth is high in water and sugars. This type of growth is especially favoured by leaf miner, aphids and other leaf sap sucking arthropods. Nutrient deficiencies results in poor vigour, less foliage and thicker shorter internodes which leads to less shading and more competition from annuals and other short lived perennials.
Plant Hygiene
Keeping trees free of dead wood and free of residual fruit after harvest will reduce the inoculums source for diseases and food sources for some pests. Removal of sick or weak annual vegetables or flowers will reduce the risk of disease amongst those plants.
Habitat Management:
Plant hygiene also relates to cover crops, wind breaks and corridor vegetation which supports the habitats of beneficial species. Most the herbivores have a narrow range of other plants as food sources other than the crops being grown, as do the beneficial predators seeking other insects and at times protein in the form of pollen and nectar. Adult green lacewings seek nectar when their favourite prey is not available, mealy bug parasites and scale parasites adults will often scavenge certain grass and herbaceous flowers for protein.
Beneficial species are more likely to live longer, be more abundant and reproduce more rapidly in natural occurring locations including farms that have a large diversity of suitable pollen and nectar resources to forage through in safety. Organic farms are more likely to contain:
* Fields that are surrounded by natural vegetation,
* Cropping systems with more diverse plant populations in or around the crops including perennials and flowering plants. We had a diverse range which included legumes, grasses, Asteraceae (Tagetes minuta in particular) which produces important nematode expellants and natural insecticides.
* Crops that are insects friendly without toxins,
* Soils that are high in organic matter and biological activity which offer protection and food throughout the year.
The science of interrelationships between a plant species, its herbivore, predator and refuge, feed source over winter and habitat species is poorly understood. Native plants like Umbelliferae’s pollen support many native Ladybirds while the parasitoid wasp Trissolus basalis is known to haunt many of the Asteraceae family when not parasitising the green vegetable bug. The little parasitoid wasps of the Diachasmimorpha sp. are predators of the Queensland fruit fly and haunt the flowers of many Gossypium sp. and probably other closely related Malvaceae sp. Australian Hover Flies like their foreign cousins visit various Asteraceae sp., Liliaceae sp. and Poaceae sp. making the later specie an important wind break understory grass. So while many of these species may appear to be weeds in the normal terminology of gardeners and farmers their use for organic farmers turns them into valuable refuge, feed sources and habitat species for known predators.
European studies have shown that conditions there require good quality natural habitats for beneficial species to be within 100m to 200m of the crops being grown. Successful biological conservation strategies are linked to many of the beneficial predatory arthropod species are most effective over distances of up to about 50m. Boller EF, Hani F, Poehling HM 2004 ‘Ecological infrastructures: Idea book on functional biodiversity at the farm level.’ IOBC wprs Commission on Integrated Production Guidelines and Endorsement: Lindau, Switzerland. http://www.iobc.ch/news.html
It is also believed that the optimum area to be dedicated to windbreak corridors for conserving biodiversity is a minimum of 15mm. This includes areas for natural vegetation micro habitats for beneficial insect species and macro organisms like birds. How relevant these studies are in Australia is untested and still has to be researched but it is though that similar areas would also be needed. The organic standards requirement is that at least 5mm of each property to be under non crop management is required. Very little actual research has been done and very little is known about specie specific interactions between pests, parasites, predators and flowering plants in Australia to make any firm recommendations on habitat management on the various types of farming operations. There is enough information available to allow producers to make an educated estimate or to logically hypothesis and evaluate this for themselves.
Dufour R (2000) Farmscaping to enhance biological control. National Centre for Appropriate Technology, Fayetteville, Arizona, USA, http://attra.ncat.org/attra-pub/PDF/farmscaping.pdf.
Altieri MA, Nicholls CI, Fritz MA (2005) ‘Manage insects on your farm – a guide to ecological strategies.’ (Sustainable Agriculture Network: Beltsville MD, USA).
http://www.sare.org/publications/insect/insect.pdf
Ekbom B, Irwin ME, Robert Y (2000) ‘Interchanges of insects between agricultural and surrounding landscapes.’ (Kluwer Academic Publishers: Netherlands).
Wratten SD, Tylianakis J (2003) Vineyard and orchard understoreys for sustainable pest and disease management. Centre for Viticulture and Oenology, Lincoln University, Canterbury, New Zealand,
Pickett CH, Bugg RL (1998) ‘Enhancing biological control: Habitat management to promote natural enemies of agricultural pests.’ (University of California Press).
We dedicated 85mm of our property to wildlife with around 10mm being directly enhanced favouring those species that would attract or be decoys for Citrus herbivores and their predators. At the time there was no research done to evaluate our position. With having a large area of land surrounding the property which was dedicated forestry a smaller area would be needed so the 5mm requested by the certifiers was a reasonable figure. Now it appears after extrapolating information from the above sites that this figure for our situation was more than adequate and probably an area of greater than 10mm would be required. To Australia’s advantage there are many areas that already suurounded by parks, bushland and wildlife corridors including National Parks which may make the 15mm more than what is needed.
In reference to pollen and nectar availability for predatory arthropods in the late winter to early spring is believed to be particularly important for increasing the health of individuals while kick starting the increase in population numbers. This therefore should be a consideration when choosing or enhancing potential resource plants in wildlife corridors and windbreaks. Local botanists, native nurseries and apriasts (Bee keepers are particularly knowledgeable in this field and are always eager to talk to interested persons. Their work place is generally lonesome as most persons do not take the time to communicate with them) along with personal experience.
Good habitat management may also be used to encourage larger predators like birds and insectivorous bats. Nesting and roosting boxes are frequently installed to attract these beneficial species, especially where their natural habitat has been reduced by agriculture and other developments. Honey eaters are exceptional insect eaters during the breeding season when protein not carbohydrates is required for nestlings. With most nesting during early spring this coincides with increased insect populations so has a strong influence on controlling insect numbers.
Planting Material
The choice of fruiting varieties in orchard trees along with the type of rootstock will have a major influence on pest and disease management. Considering citrus plants, those plants grafted onto Sweet Orange or Trifoliata are better suited to heavier soils where Phytophthora fungi may be prevalent while Rough Lemon has a greater tolerance to higher salt levels and Citrus Nematode. We also found by experience that the early Clemantine Mandarins were more susceptible to Queensland fruit fly while Emperor Mandarins performed better during drought years and without irrigation compared to the Imperial mandarin which performed better in most seasons near the coast.
Vegetable growing needs to be considered at in a similar manner. We grew poppies for seed in years where we were expecting below average temperatures in winter while calendulas performed better during winters where above average temperatures were experienced
Mating Disruption
The females of many insect species like many flowers produce sex pheromones to attract males for mating or males to transport pollen from one flower to another. The light brown apple moth or Codling moth are prime examples of female pheromone attraction. Mating disruption is a pest management technique employed that literally smothers the fields or orchard in synthetic pheromones similar to what the female releases. This sends the males into an exciting thither reducing the chance of them locating and mating with a female. While pheromone activity is specific to a specific species it probably has little interference with the feeding habit of predators.
Pesticides
We never considered the use of pesticides on our farm or in the orchard, following the disgusting answer we received that day “Don’t worry about it no one else does”. Pesticides are applied to ecosystems, not just to the target pests. This is a critical point to consider as humans we should not have toxic crops foisted upon us disguised as fresh and healthy without the appropriate withholding periods or labeling. Imagine conventional grown food being labeled “sprayed with xxxxxxx pesticide or grown with xxxxx herbicide.” In reality it is the “Organic label” that is stating “NOT sprayed with xxxxxxx pesticide or not grown with xxxxx herbicide.” Why is it that most products have to include what is mixed with the product like sugar, preservative xxxxxx but fresh food is exempt from such labelling?
In fact I am being serious all other products marketed for consumption or body contact products must be labeled with their contents. It is the manufactures or value adders responsibility by law to conform to government law yet conventional farmers using these toxic compounds escape their responsibility to declare their inputs and properly inform consumers of what they are actually buying. The additional overall costs of the product which the consumer would inevitably pay for is miniscule in the overall scheme. For example the cost of the herb binding tape printed against being plain would be insignificant. Prepacked labels in a case of citrus or other fruits could be displayed on the shelves below or above the products being sold or on the individual cartons. This could be placed on the bottom of a punnet if necessary. It would only take a little thought to overcome the difficulties and claims made of impossible and too unyielding to conform to. We have all heard the arguments before and nothing is impossible if we really want to achieve it.
Predatory insects which come into contact within the withholding period are also directly affected and are often eliminated at the same time from the scene. It should also be remembered that the withholding toxic period for a predatory insect is far greater than the withholding period for a human and withholding periods are suppose to be designed with human tolerances not the targeted organisms tolerances. Also consider that there is on average 1 predatory arthropod to every 10 herbivores and once the herbivores are weakened they are easier prey for the predators which then also succumb to the pesticide having a multiplying affect in the environment.
Many non target adverse impacts are the result of using chemical warfare which reach well up the food chain. This also applies to organically acceptable pesticides especially spinose/d, pyrethrum, oil and sulphur which are harmful to many beneficial species. The advantage of organically approved pesticides are that they are usually used more responsibly and target a particular herbivore, the withholding period is much shorter and the affects along the food chain are no where near as sever as those from the toxic chemical alternatives. The impact of pesticides depends on the timing and rate of application and the species being targeted. Oil sprays are particularly dangerous to all members of the food chain which come into contact with it and though registered for organic use should be avoided in the long term.
It has been well documented in the past where birds have succumbed to eating insects that have been sprayed with pesticides or fungicides and probably herbicides. One evening while at athletics training at the Carbrook State Primary School my daughter found a Noisy Minor (Manorina flavigula) then the girls found another and before long the boys came across another bird. In total 4 birds were rescued that day all unable to fly and suffering from sever and uncontrollable twitching and convulsions. With care all the birds survived the short term and were released but what the long term affects were we will never know. The local vet diagnosed the birds claiming they were suffering “typical pesticide symptoms.” Consider that most pesticides if not all cause shell thinning which results in broken eggs the future didn’t look good for these birds and the farm involved adds to their cycle of insect woes.
To avoid or minimize adverse effects of organic pesticides, growers should make their decision on which pesticide to use based on:
* There being no alternative biological control readily available,
* Apply the product only when its use is absolutely necessary as indicated by previous and accumulated monitoring,
* Which pesticide is the most appropriate for the targeted pest, selective and has the lowest impact on the environment and beneficial predators,
* Follow the label directions and or use in accordance with state regulations,
* Spot spraying of the infested area/s and adjacent plants is to be used in preference to blanket spraying,
* Use the right equipment in the correct manner at the most opportune time, to maximize the greatest efficiency and to minimize the need for repeat treatments,
* Monitor the effectiveness of any pesticide use to allow future applications to be fine tuned or to find alternative biological means as a treatment.
Refining the use of pesticides growers should make themselves aware of the following situations:
* What can I do in the meantime differently to avoid the problem in the future from reoccurring or to minimize the chances of the problem reappearing?
* What can I do in the meantime differently to ensure a better balance where the outbreak has minimal impact,
* How could I handle it better next time if the situation presents itself again?
* What might I do different next time if the situation presented itself again?
* What am I targeting and why am I targeting it?
* Is it really necessary to use a pesticide at this moment- Can I wait a little longer?
* Was the spray effective against the target?
* Was the spray mix the correct one and was the concentration adapted correctly for the target pest?
* Was it adequately mixed which is especially important for oil sprays?
* Was the timing optimal for the targeted pest? That is did the spray contact the target when it was most vulnerable?
* Was the desired result worth the costs, labour and habitat damage?
* What were the affects of any spray drift?
* Was it necessary to repeat the operation?
* What will the long term impacts be on the environment?
* What will the long term impacts be on the users and my/their families?
* Can I use an alternative biological control?
By implementing a basic monitoring plan with good healthy, specie targeted windbreaks and or wild life corridors with good understory plantings pesticides can be eliminated all together.
Weed Management
Organic farmers are usually daunted at the thought of weed control and I was no exception in the early days. In the late 70’s and 80’s, even in the 90’s the local council was still hell bent on weed eradication programs instead of weed suppression or control. I have mentioned in several chapters the local council insisting that every noxious weed should be eradicated immediately on site with toxic poisonous synthetic chemicals instead of a basic formulated long term management policy that saw the control and eventual submission of targeted noxious weeds with organic procedures. Improve or change the ecosystem to a point where it replicates the local natural ecosystem so that the local species again dominate the scene.
Part of the problem as I saw it was the zealous protection of a narrow minded cult who could only see the eradication of weeds through the spray jests of their tractors, machinery, legislation and self preservation. They refused to allow organic farmers their right to challenge the system and use alternative proven practices of improving pastures, farmland, orchards and plantations to a point where the noxious weeds could nor persevere and the stored seed bank reserves were totally depleted. Our farm and orchard stands testimony to the eventual eradication of unwanted species like Parramatta Grass, Fire Weed, Patterson’s Curse, Scotch Thistle and the much heralded Xanthium Burr. I accept in some cases like those of Malvaceae the soil seed banks could last for a hundred years or so but these seeds can be made not to germinate by making ground conditions hostile to them. The xanthium species found in our orchard appeared late after the other noxious weeds had all succumbed but 2 years later they too disappeared as quickly as they shot up. Fortunately they only appeared sporadically in the orchard over a few years. It is known the seeds can live for up to 30 or more years so the seeds may have been in the soil from the time the old dairy farm was in use some 45 years before. By not allowing it to seed assists in the depleting of the soil seed reserves.
Defining what a weed is depends on your point of view. Weeds could be defined as plants that exhibit some of the following characteristics:
* Plants which compete with crops for water,
* Plants which compete with crops for nutrients,
* Plants which compete with crops for available light interrupting photosynthesis,
* Plants which interfere with irrigation low level sprinklers,
* Plants which interfere with harvesting or other operations,
* Plants which compete with more desirable cover crops and legumes,
* Plants which increase the risk of pests,
* Plants which encourage fungal or other pathogens which support other plants other than the crops being grown,
* Plants which produce spiky seeds or other udesirable physical features that inconvenience or injure workers,
* Plants which have the potential to invade neighbouring properties including areas of native vegetation,
Remember “One mans meat is another mans poison.” What is a weed to the non organic farmer is mulch, green manure and ground cover to the organic farmer. The green Parramatta grass seeds, a declared noxious weed, were harvested and mixed with the duck’s evening rashes, the Patterson’s Curse and Scotch Thistles were incorporated into beautiful compost and mulch, as was the Xanthium Burr. While many struggled to eradicate these so called weeds we were busily harvesting them with the slasher putting them to use beneath the trees, few had to be removed by hand as they grew too close to the trees or sprinkler lines.
Our worst weed to control was Rag weed yet it was not declared a noxious weed. This weed appeared in the recycled muds, silts which were recovered from the dam when it was built and used on the vegetable patch and flower seed beds. At first there appeared to be no problem but when lime was added to the area with blood and bone the seeds exploded into life. An initial shallow rotary hoeing knocked down the first seedlings followed by heat treatment with a gas burner was used to knock down the second lot of seedlings. We then planted the vegetable and flower seedlings immediately covering the beds and furrows with a thick layer of sawdust 75mm to 100mm thick to suppress the seeds from germinating. The surrounding area had to be grubbed regularly to eliminate young plants and prevent them from reaching a stage of flowering. The above had to be repeated on all consequent plantings and on the surrounding area until the small forested area had a complete canopy. It took nearly 8 years for the Rag Weed to abate and only after we planted the area with lemons where regular slashing with good cover crops assisted in its demise.
While the sawdust was good at suppression it in no way eradicated the rag weed. We also noted that old saw dust decomposed quicker and allowed Rag weed seeds to germinate prior to full decomposition causing problems and root nutrient competition just as the flowers appeared. Fresh sawdust lasted the whole period through to the end of harvesting so became our preferred medium for mulching.
For example Colloff MJ, Fokstuen G, Boland T (2003) ‘Toward the
triple bottom line in sustainable horticulture: Biodiversity, ecosystem services and an environmental management system for citrus orchards in the Riverland of South Australia.’ (CSIRO Entomology: Canberra).
http://www.ecosystemservicesproject.org/html/publications/docs/soil_final_report.pdf
Researched and compared weed management times between organic regimes and non organic regimes was typically seen as more labour intensive with organics than non organics. The study on several Riverland citrus orchards found the labour requirement for weed management on organic groves was 11.5 hours longer per hectare per year which was three times that of non organic groves. To keep this in perspective however, weed management only accounted for 3mm to 7mm of the total labour input on those organic orchards. That is between 1.5 hours to 3 hours a week. I can associate with these times as we spent closer to the upper limit maintaining good cover crops on the inter rows slashing triweekly during summer and autumn with monthly slashings during spring and hand control.
In the case of the vegetable and flower plots this would have increased dramatically as the half hectare plot would take several hours to cover with the burner and several days to cover with sawdust plus hand pulling of weeds that either blew in or were more resistant and grew through the saw dust. It was interesting to note that no Eucalyptus species, Acacia specie or other native plants germinated in this plot to our knowledge but were prevalent on the reforested area between the plot and the dam. The time spent on this plot is estimated at 16mm to 18mm of the total time per hectare per year.
Pre planting weed management
As organic producers are unable to use systemic herbicides it would be easier to tackle weeds in the prospective orchard or farm plot/s in open country than amongst established trees and vegetable prior to planting or conversion. A serious management plan should be orchestrated against perennial weeds like couch grass (Cynodon sp.), kikuyu (Pennisetum clandestinum), Johnson grass (Sorghum halepense) and nutgrass (Cyperus rotundus) and any other persistent problemsome plant that is already established on the farm or orchard. One method that can be easily managed and is often overlooked if suitable fencing is already installed is “Overgrazing.”
Overgrazing
The use of a deep ripper and pigs is highly effective against all the grasses listed above especially Cyperus rotundus which will see them root for the nuts hours on end. Pigs are the only method which can completely eradicate this highly invasive almost impossible grass. The added advantage is these animals can be sold as organic conversion or be part of the organic management process. While long term maybe 6 months overgrazing is highly affective offering a monetary return at the same time.
Stocking rates over this period would unfortunately be in excess of the recommended organic rate but is short term without any side affects on the animals or plots involved. Contact your certifying body as you may get an exemption for the higher stock numbers for the period it takes to eradicate the problem plant as an alternative organic approach. Overstocking does not include bedding, water supply or housing though. The stocking rate for pigs is 12 sows with 1 bore per hectare organic but this would be insufficient to bare the ground in a short period. The non organic rates are 24 sows with 1 bore per hectare and even this may need to be upped a little to hasten the efficiency of control. Chickens could also be used as they scratch but won’t dig as deep as the pigs especially in hard ground. A combination of pigs and chickens is another alternative which could be investigated. The advantage here is that eggs can be collected from the onset and sold before they reach their use by date fetching higher prices on the broiler meat market. Remember though that pigs like eggs to eat so the eggs maybe out for selling so meat birds should be considered as a more viable alternative.
Plants are only weeds when they cause, or are very likely to cause, economic loss, other losses or impact on the health of crops on the farm or in the orchard or neighbouring properties. Volunteer plants are self sown plants that occur in orchards and plantations amongst sown legumes and grasses. Their impact as mulches in orchards or plantations can be quite significant. The manager’s job is made easier if he classifies “real weeds” as those that require attention and need to be eradicated or reduced to a manageable level and “volunteer plants as green mulches” that can be used to his advantage as mulches, compost or green manure. Volunteer plant’s negative impacts must be weighed against the potential advantages with in the orchard or plantation to determine whether they need to be removed immediately or allowed to grow as a mulch or compost. Some of these advantages can be seen as:
* Most volunteer plants reduce the need for sowing annuals and actually assist in reducing weed time spent on weed control management,
* Most plants cover and protect the soil from the effects of sun, wind and rain thus mitigating many erosion problems,
* Most plants are a reasonable food source for beneficial invertebrates supplying pollen and nectar for beneficial predators and parasites of crop herbivores internally and externally of the farm,
* Many plants can be food sources to other domestic animals like pigs, fowls, guinea pigs, sheep, goats and even fish,
* Nutrient recycling from deep rooted species absorb nutrients from lower soil profiles bringing them to the surface and redistribute them as the plants decompose on the surface making them available to soil organisms and again to the plant instead or being leached or removed from the property,
* Plants aid in the regulation of soil temperatures and moisture,
* Weed suppression by volunteer plants aids the efforts of sown legumes and grasses to suppress the development of undesirable real weeds like.
Indicators of soil conditions
Volunteer plants unlike crop plants; that grow where we have designed and planned their existence, thrive under conditions which best suit their personal traits. The study of volunteer annuals are often very reliable indicators of latent soil conditions. These can include high or low nutrient levels, soil compaction, salinity, fungal or micro organism present in the soil. Altering the soil microbiology will enhance or decrease the number of undesirable weeds or volunteer plants. Increasing the soils micro biology increases the competitiveness of more desirable cover crop species leading to greater diversity and the total biomass of the soil.
During the second to third year of management it was noticed that there was a marked decline in Parramatta Grass indicating soil improvement and a huge increase in thistles especially Scotch Thistle which is a great indicator that the soil is in a rapid state of increase or decreased soil fertility but the fertility rate of change was dramatic. The Scotch Thistle had trunks of 50mm to 80mm in diameter and reached in excess of 2 meters in height in places. They were allowed to seed but were knocked down for mulch as they began to disperse their seeds. This allowed for the greatest volume of mulch and stored energy to be returned to the soil. By the fourth year the thistle went into decline at the same time as the Gallium sp. began to appear.
The greater the diversity in cover crops in a habit means the greater the variation in root structure and depth, height and type of foliage, flower type and timing, root exudates, root hyphae which all add to the complexity of interactions between ground cover plants, green manures, volunteers in the plantation or orchard trees and the soil organisms. There is now considerable evidence that the greater the diversity in cover crops the greater the health of the whole agroecosystem. In our case the trees produced more fruit, more consistent over several seasons with better flavour, colour and moisture content within the fruit with fewer inputs including water. It is important to note that compost, mulches along with the lack of chemicals also played a part in the trees health and no single unit could be singled out as the main reason for the trees overall performances.
Integrated weed management
Organic integrated weed management (IWM) is all about achieving the most effective weed management methods for your individual farm or orchard in both the short term and long term.
Successful IWM relies upon some basic principles which include:
* Correctly identifying what are weeds and what are volunteer plants so that you can encourage or suppress and control,
* Understanding and interpretation of weed ecology in your district will allow you to know why the weeds grow where they are, how they got there and what they mean to the soil,
* Allows you to select the most appropriate and effective management methods to mitigate negative impacts on the farm environment,
* Allows you to plan in advance weed management programs so that they can be effectively timed to reduce seed set or set seeds,
Monitoring allows you to be in control and to plan effective strategies of several mulching integration techniques into a program which are the most cost efficient for your farm project as:
* Some weeds are easier to control than others,
* Some weeds are annual while some are perennial,
* Some are spread by cultivation while others are spread by wind or water,
* Some are avoided by foragers while others are attractive to foragers – The ducks avoided Rag Weed,
* Some are distributed by foragers,
* Some are very competitive against cover crops.
A combination of weed control techniques also helps to reduce the risk of particular weeds dominating the orchard. When selecting techniques, producers should consider potential long term impacts of their choice and ideally move away from high impact activity like continual cultivation. In subtropical regions, levels of soil microbial biomass, organic matter, nitrogen and activity of mycorrhizal fungi and phosphorus solubilizing bacteria all increased dramatically after only three years where slashing, hand removal and grubbing were the only control techniques incorporated into the farm or orchard compared to cultivation or herbicide use on adjacent properties. These results were certainly significant on in our orchard as dramatic increases were seen between the second and third year. We broadcasted white Haifa trifoliate along with rye grass, native Paspalum and Kangaroo Grass (Themeda australis) for there respective but different characteristics which included nitrogen fixing, deep root penetration, bulk and tolerances to strongly acidic soils. The Paspalum needed to be slashed prior to seeding because of its vigor, the Themeda australis was a perennial and dies out naturally as did the rye grass after several years despite allowing many plants to set seed while the clover become the dominant species along with Kikuyu (Pennisetum clandestinum).
After pains takingly trying to eliminate the Kikuyu we decided it was better to mange it and use it as an aggressive fast growing mulch with high biomass. Interestingly our approach still saw the clover dominate the inter rows some 10 years later. The following 2 manuals provide useful guides to producers wanting to develop a more holistic approach to weed management.
Ministry of Agriculture Food and Fisheries (2002) ‘Seven steps to managing your weeds.’ (Province of British Columbia).
http://www.weedsbc.ca/pdf/7StepsToManagingYourWeeds.pdf
Ito M, Ueki K (1981) Approaches to weed management in citrus from the aspect of weed science. Proceedings of the International Society of Citriculture2, Pages 483 to 485.
Short Term & Long Term Approach
Short term aims include whether the area is to be planted as pastures, inter row plantings or mulch followed by the choice of preferred plants. Reducing the biomass of weeds and preferred specie growth during critical periods in the orchard or plantation is critical beneath the drip lines during flowering and early fruit set. This can be achieved by dropping the slasher lower along the tree lines or close to the trees. As the trees mature the canopy will be self shading making this unnecessary or less important.
Long term approaches include altering the species in the inter rows by sowing different species, suppressing or eradicating existing species. The eventual dominance and encouragement of both clover as a legume, kikuya and reseeding of native Paspalum species for bulk gave what we considered a good balance with other volunteer species for the orchard while feeding the ducks. It was also noticed that the Galium sp. germinated in the shaded areas surrounding the trunks and spread quickly outwards over the surrounding grasses and up the outer foliage of the trees on the north east and western sides of the trees,
Personally I would like to see some trials done with both Crotalaria juncea and Tagetes minuata; (See below under Water and Nutrition management), together as they could supply large bio mass, nitrogen fixation, weed suppression, undesirable nematode reduction and soil structure improvement quicker than any other combination in the short term. These can then be followed up with more manageable cover crops like Themeda sp., Haifa trifolia and volunteer sp. long term to create a balance in soil nutrient reserves.
Keep Weed Management Objectives Realistic
For producers and their workers Preventing further seed set is the most effective and realistic goal to eradicating or controlling problematic weeds. We started harvesting what was an infestation of one of the most problematic weeds in the district – Parramatta Grass.
After harvesting the green seeds they were mixed into the ducks evening food. The drakes were locked up and their manure harvested for 5 days. The manures were then mixed with sand and watered. The results of this experiment showed that no Parramatta grass seed germinated which was then the basis of eradicating this weed from the entire farm. Later experiments using worm castings also showed that Parramatta grass seeds failed to germinate in trials carried out over 2 years. These same trials did however produce an interesting result in that worm casting did not kill white Haifa trifoliate seeds which not only germinated but had excellent microbial nodule development without the need for inoculation.
This proved the most effective method for us to control and eventually eradicate the Parramatta grass, was through harvesting green seeds not allowing them to ripen and feed them to the ducks as a supplement to their food. The ducks resting under the trees in the heat of summer also flattened and eliminated the plants from around the base of the trunks.
Ngouajio M, McGiffen ME (2002) Going organic changes weed population dynamics. HortTechnology 12 (4), Pages 590 to 596 discovered that where a herbicide program was in place prior to converting to organic management, one weed issue which is likely to be confronted is the reemergence of weeds that were most sensitive to the herbicides being used prior to conversion. This information is extraordinary as the use of herbicides is suppose to eliminate weeds not encourage the emergence of the problem.
Quarantine
Quarantining of plants and animals can minimize the introduction of new weeds onto the farm or orchard, and their spread between blocks. Preventative measures are far more cost effective compared to the resources required to suppress weeds, pests or disease once they become established.
Effective quarantine approaches can include:
* Restrict the movement of machinery, people and livestock onto and
across the whole property, especially those coming from locations where known weed infestations occur,
* Newly purchased live stock including fowls should be quarantined for a minimum of 5 days for poultry and 10 days for hoofed animals to ensure that any seeds that may cause a problem have fully passed through the gut and out of the body,
* Establish buffers zones, including windbreaks and surface water diversion, against wind and water borne seeds.
Hygiene
Hygiene involves practices that reduce the introduction and spread of weeds into the orchard or onto the farm and pastures and producers should be aware of how to:
* Select clean disease and weed free sources of potted trees, mulch, compost ingredients and other materials that may be weed infested,
* Bare rooted trees is a good method of preventing the introduction of pests and weeds,
* Avoid spreading weeds vegetatively, e.g. avoid cultivating from infestations of perennial weeds like nutgrass (Cyperus rotundus), couch (Cynodon sp.) or Kikuyu (Pennisetum clandestinum) into clean areas of the enterprise,
* Clean equipment thoroughly of plant material, bulbs, roots and soil before it is taken into clean areas or the enterprise,
* Prevent weeds from setting seed,
* Destroy seed of noxious weeds by deep burial, burning, etc. Grazing is not always reliable as the seed of many weeds is viable after passing through grazing animals.
Animal manures will contain large amounts of weed seed unless the animals have been fed crushed grains or the manure has been treated in some way which may include heat. This means that when manures enter the enterprise there is a real risk of weed infection.
When mature seed heads of marshmallow (Malva parviflora) are eaten by sheep, about 20mm of the seed excreted in manure is still viable with viable seeds excreted for up to seven days. Michael PJ, et al. (2006) Sheep rumen digestion and transmission of weedy Malva parviflora seeds. Australian Journal of Experimental Agriculture 46, Pages 1251 to 1256.
This means that an eight day ‘withholding period’ would be required after grazing on marshmallow, for sheep manure to be free of its seed. The importance of hygiene as a management technique was stressed in an overseas trial by Dastgheib F (1989) Relative importance of crop seed, manure and irrigation water as sources of weed infestation. Weed Research 29, Pages 113 to 116 who found sheep manure to contain roughly 330,000 seeds per tonne, including wild radish, marshmallow and amaranth.
As stated earlier effective composting where temperatures range from 60°C to 75°C for 3 consecutive days will eradicate 99mm of viable weed seeds in manure and is the best single method of eradicating the risk of introducing new unwanted weed seeds.
Water and Nutrition Management
In high rainfall areas where inter row or pasture growth for composting is much more abundant. The broadcasting of nutrient inputs over the whole orchard floor is far more beneficial as it supports better root development of trees, creates greater biomass in cover crops and green manures which can be slashed and used as mulch for weed suppression in the tree rows or used as compost for other farm activities.
Different cover crops yield different quantities of bio mass. The department of Agriculture and food field experiments produced 5.4 tonnes per hectare of biomass in barley with 2 summer slashings of the crop. This did not take into account root or stubble remains.
Another high biomass annual is Tagetes minuata an Astaraceae which has been noted by the author to improve soil structure dramatically. It can be grown as a summer crop in frost free zones where it was estimated that in excess of 12 tonnes per crop of biomass was possible in well composted fields prior to planting and harvested prior to seeding.
In low rainfall districts, irrigation and nutrition programs minimize the supply of water and nutrients to weeds especially in the inter rows and pastures. Nutrient is concentrated within the tree drip lines rather than being broadcast over the entire ground area. Reduced nitrogen input into the inter rows are also likely to favour dry land legumes like Lupinus varieties, Medicargo sp. and Viccia sp.. Legume growth may be more desirable than grasses and other non legumes. It must be remembered that most legumes detract somewhat from biomass. Crotalaria juncea is the major exception.
Competition
In 350BC, Aristotle claimed that “nature abhors a vacuum.” In terms of weeds his theory certainly applies in all ecosystems. Bare soils are very quickly occupied by volunteer plants ready to take advantage of the vacuum created for what ever reason. As a result, producers who endeavour to maintain their orchard in a state of bareness free of vegetable matter face a prolonged uphill battle against all the elements of nature. This unnatural imbalance will lead to conflict within natural struggling to gain dominance and conflict with the producer trying to eradicate the vacuum which ultimately will implode on the producer.
It is far more practical to remove the vacuum by planting desirable plants to improve soil structure, fertility and suppress weeds in the inter rows and pastures for mulch or compost.
Select desirable crops as per the criteria for short and long term cover crops and with:
* The time to develop full ground cover which is usually the sooner the better for biomass and long term for nutrient input,
* The density of cover crop should be looked at as the denser the better short term and balance of bio mass with nutrient supplement for the long term being better,
* The duration of cover crop being annuals initially with perennials in the longer term being better)
Competitive suppression crops short term have been mentioned above as have the long term ground covers.
Allelopathy
Allelopathy is a special form of competition, where seed germination or plant growth is suppressed by chemical substances produced by another plant. These substances may be leached from foliage or secreted from roots of the allelopathic plant and or released when the plant dies and decomposes. Green manure crops is one method to use allelopathy in orchards and pastures. Barley and rye are known to suppress numerous weed species and are considered to have good allelopathic potential in medium to long term cover crops. Excellent examples of allelopathy is seen beneath Casuarina sp. and Allocasuarina sp. forests and Bracken Fern (Pteridium esculentum) where the weed growth has been entirely eliminated.
Slashing
Slashing is considered the most cost effective approach by organic orchardists to keep cover crops and weeds to a manageable height. It is relatively fast and causes minimal soil disturbance. Small light weight tractors with a small side discharge slashers are generally more efficient and cause less soil compaction than larger more cumbersome machines. It is important not to slash in wet weather as soil compaction is more likely. Height adjustments for slashing are important considerations and are chosen to suit the weed management objectives. Slashing during or before flowering of weeds will prevent seed production while slashing after flowering will allow desirable plants to self generate. The maximum biomass is generally attained with growths of 150mm to 300mm of height depending on the cover. The higher the growth of the ground cover the lower the risk of compaction but the lower the biomass will be. We generally slashed the inter row growth when it attained a height of 200mm to 300mm in height reducing the height to around 80mm in height. At the peak of growth in late summer and Autumn this meant we were slashing fortnightly to every three weeks. We used a 20 horse power tractor with a 1 meter side discharge slasher with two cuts on each side of the trees directed towards the trees once the trees had matured.
Brush cutters are very affective close to trees and irrigation equipment. I always carried irrigation risers in my back pocket with sprinkler heads and a pocket knife for the expected miss. Well none of us are perfect. The coarser material produced by slashers compared to flail and mulch mowers will break down more slowly and extend the life of the mulch. Mulch mowers are also much harsher on beneficial insects living in the inter rows. Organic orchardists should consider slashing alternate rows, allowing the uncut rows to provide resources such as pollen for beneficial insects and mites in the orchard. Our orchard consisted initially of 5 cuts in the inter rows with a 1 meter wide slasher. By the time the orchard was rin maturity the cuts had been restricted to 2 rows plus a 100mm to 300mm strip down the center which was allowed to mature and seed unless an undesirable plant showed its head.
Heat
Thermal weed control comes in several forms from radiant, flame and steam to kill plant tissue. These techniques have been researched extensively and have been used to control weeds for many years. They are generally economically effective only against seedlings though they do set more advanced plants back to varying degrees. Thermal weeding is therefore used most commonly on row crops and seed beds to kill the new flush of weed seedlings prior to the preferred crop emerging.
A big advantage of thermal weed control is that it does not disturb the soil. Organisms below the soil surface are generally not affected, as the heat does not penetrate far into the soil. A disadvantage of thermal weeding is its high energy cost monetary wise and environmentally speaking. Heat control is best used in conjunction with bed mulching.
Solarization
Solarization involves the destruction of vegetation including seeds, pests and pathogens by trapping solar heat between the soil and a clear, plastic, sheet during hot weather for several days or weeks. It will kill all organisms in the top 50mm to 100mm of soil including both pests and beneficial ones. We used this method in part of the vegetable, flower seed production area. We allowed the plastic to lie for 6 weeks in air temperatures of up to 38 degrees. We then sowed into the top couple of millimeters with out adding any mulch. we were pleased that no weeds presented themselves but were later overtaken with Rumex brownii which proved to be very difficult to control while the crop was being grown. Digging out the tubers proved ineffectual as they continued to shoot from broken pieces. and needed to be constantly cut back .
Solarisation requires good heat transfer into the soil. The soil needs to be moisture to wet, all air gaps between the plastic and soil must be sealed to eliminate heat escaping and wind from lifting the edges of the plastic sheet. The plastic must remain in place for at least four weeks. The time will vary with the quality of the plastic sheeting, the prevailing external air temperatures and weed species. Winter annuals are generally less tolerant of high temperatures than summer perennials or dry schlerophyll forest shrubs.
Reinfestation of treated areas with weeds can be avoided by mulching, sowing green manures, cover crops or mulching and sowing vegetable or flower seedlings immediately the plastic is removed.
Mulching
Mulch inhibits seed germination by blocking sunlight from reaching the soil surface and warming of the soil surface. It is also a physical barrier to weed growth. Some mulches also act as allelopathic inhibitors by releasing chemicals into the soil. Almost any organic matter can be used as mulch, but straw, compost and chipped green waste are the materials used most commonly in orchards. Grape marc is also popular in viticulture areas, as is sugar cane bagass in cane growing areas when available. Eucalyptus sp. woodchip and sawdust has also been used successfully for weed suppression and soil improvement but should not be obtained from mills specializing in wood chip. The raw materials need to be a byproduct of a value adding industry making the chips a waste product.
Mulch are generally used along the tree rows at 70mm to 100mm in depth however we also used the sawdust mulch at 10mm to 20mm in depth in the inter rows where the Haifa trifoliate thrived.
Mulches generally:
* Provide a source of nutrients whether they are high in nitrogen or carbon,
* Add organic matter to the soil and contain good quantities of humic acid,
* Enhance soil biology dramatically increasing microbial activity at different stages of their decomposition,
* Protect shallow rooted species like citrus roots from excessive heat and drying out,
* They conserve soil moisture by reducing evaporation and in the case of citrus the soil moisture tension is reduced by up to 20mm,
* They increase the aeration by opening up airways in heavier soils and combine sandy particles with humus in sandier soils,
* They provide a distinct demarcation line which protects tree trunks, sprinklers and irrigation tubing make cultivation and slashing less intrusive along the tree rows.
Trials in Egypt by; Abouziena HF, et al. (2008) Comparison of weed suppression and mandarin fruit yield and quality obtained with organic mulches, synthetic mulches, cultivation and glyphosate.
HortScience 43(3), pages 795 to 799, on weed management in citrus orchards experienced better control of grasses and broadleaf weeds with a 60mm covering of wild oats (Avena fatua). This could be because the straw may have a stronger or better allelopathic reaction with those soils with local grasses and broad leaf weeds.
Mulches do have some disadvantages though I consider these to be minor but are best noted:
* Mulch may harbour pests such as snails and slugs– enter the ducks and bright orange yokes,
* Partly decomposed mulches often create an ideal seedbed for weed seedlings – Enter the ducks who love fresh green shoots for breakfast,
* weeds at the mulch, mid row interface can be awkward to manage without disturbing the mulch. We just slashed along the line finding that excessive green mulch often accumulated along the interface beneath the drip line,
* Mulches often shed sprinkler water and light rainfall away from the trees and towards the drip line so should be kept just within the trees drip line or well scratched until the particles are properly moistened on beds. This was especially noted when finer mulches like saw dust, rice hulls and the like were used. Mulches with variable size pieces like sugar cane bagass had the opposite affect allowing water to percolate vertically downwards however they do absorb large amounts of moisture,
* Kikuya and couch are favoured by mulches which they penetrate very easily,
* Mulches can tie up nitrogen in the early satges until a balance is reached on the farm,
* Weeds alongside a mulched area should not be permitted to mature and set seeds onto the mulch otherwise the weed suppressing role of the mulch will be severely compromised unless the ground cover or green manure is no cause of concern,
* Mulches can be readily disturbed by fowls especially chickens which love to scratch,
* Some mulches can be blown away by strong winds like rice hulls or removed by medium to fast flowing water.
Some farms that are placed near sugar mills, saw mills, rice growing areas or wineries may have a huge advantage in being able to access good reliable cheap supplies of bulk mulches. In our case the cost of transport meant we were paying about $0:80 a cubic meter in 1994 for saw dust and often had smaller 20 cubic meter loads dropped in for the cost of a carton of mandarins or oranges to the staff on the way home from work.
On site production of organic matter can reduce the cost of mulching dramatically as it is part and parcel of the green manure, ground cover maintenance program, especially if the slashed matter becomes the mulch. The single pass with a side throw slasher delivers the material directly under the trees or can be collected at intervals for composting. This approach particularly suits organic orchards as it reduces both the need for external large inputs and the risk of introducing new weeds in some materials.
Synthetic mulches
Weed mats are being extensively used to great effect in local stone fruit orchards and blue berry farms. Woven plastic matting is generally discouraged on organic farms but is allowed as a last resort. When synthetic plastic mats are used the mats must eventually be removed from the environment and not be cultivated in or left on site.
Temporary mulches of black plastic can be used to kill difficult weeds including couch though organic standards generally prohibit the use of solid plastic sheeting as mulch for weed control but special permission may be granted if no alternative method can be found.
Biological control
Biological control programs are really in their infancy and are generally not acted upon by governments before the problem has covered an extensive area and is costing the community and farmers a lot. The best example of biological control still rests with the introduction of the Cactoblastis cactorum moth on Prickly Pear. (Opuntia sp.)
Mechanical cultivation
While cultivating, the soil may destroy unwanted plants it is highly destructive to soil structure and to soil organisms.
In fact cultivation:
* Increases unwanted plants by bringing seeds in the soil seed bank to the surface where they will germinate,
* Stimulate tubers and rhizomes into growing,
* Is relatively more energy expensive,
* Increases soil compaction leading to anaerobic conditions, greater water run off and less moisture holding capacity within the soil.
Many orchard trees develop many shallow feeder roots, especially under mulches where conditions are more conducive for maintaining cooler, moister and greater biological activity. This increases the likelihood of infection if the roots are damaged and decreases the ability of the plants to feed the rest of the tree until the feeder roots are reestablished.
Manual cultivation
Most producers rely on some manual weeding like hand pulling, hoeing and brush cutting to remove weeds from around young trees, sprinklers and in furrows between growing beds where mechanical cultivation and slashing is too risky or impractical. Manual weeding is very affective but is labour intensive and therefore costly. It has one big advantage that it gives producers the opportunity to closely observe and monitor their soil and trees which is an important aspect organic management.
Chemical Weed Control Trials
Organic herbicides based on pine oil, natural acids from other plants are acceptable to most organic certifiers. These herbicides disrupt the cuticle of plants and cause them to desiccate. These herbicides still involve the application of chemicals and though they may seem rather benign they still have an accumulative affect in the soil and may also cause the disruption of microbiological activity until neutralized. They should be used sparingly and with care as the effects of their long term use and soil disruption have still yet to be clarified.
Tests we carried out with pine oil on Kikuya (Pennisetum clandestinum) on a small patch in the orchard proved that while being affective required several applications rendering it very costly to maintain or to cover the whole area which was affected. To completely eradicate the Kikuya would also mean either painting affected plants to restrict spray and the eradication of other desirable ground cover plants like Haifa trifoliate which was not acceptable to us. The use of pine oil or other vegetive oils may have better results on vegetable and flower seedlings prior to the such seeds emerging. We tested both pine oil and Eucalyptus oils on leeks prior to the Leek and radish seeds emerging with good knockdown results. We decided not to continue using the oils as the cost factor was high and heat treatment via gas burner was just as affective.
Timing Timing & Timing!
Where as Position Position Position is the essence of retailers and to a lesser degree manufactures timing can be the priority for weed control. Seedlings develop more profusely accordingly to weather conditions. Weed management actions should be prioritized if possible to match the targeted plants weaknesses for optimum results.
The most opportune time to knockdown plants to prevent seed set, then is as the first flowers appear which also gives the producer the maximum biomass from the plant at the same time. A single plant of black nightshade (Solanum nigrum) may produce over 170,000 seeds, some of which can remain viable for over 20 years. Whittet JN 1968 ‘Weeds.’ (NSW Dept. of Agriculture, Farmers’ Handbook series).
The most opportune time for suppressing weeds through cultivation is during hot dry periods. This is especially important for plants with rhizomes so try and avoid cool moist periods.
Couch: Cynodon dactylon aFarmers Nightmare
Couch has been proclaimed as one of the world’s worst weeds and causes problems for organic and conventional producers everywhere. This is one native that has been adopted extensively worldwide as a high class, hard wearing lawn grass but has turned out to be a nightmare when it comes to eradicating it from agricultural farm land.
This grass not only competes for water and nutrients but it also suppresses many orchard crops and other crops through allelopathic effects making it more of a pest. Couch retards the growth of young citrus plants significantly through the allelopathic substances released even months after it has been killed. Horowitz M (1973) Competitive effects of three perennial weeds, Cynodon dactylon (L.) Pers., Cyperus rotundus L. and Sorghum halepense (L.) Pers., on young citrus. Journal of Horticultural Science 48 (2), Pages 135 to 147.
Mature citrus trees are also affected by heavy infestations are affected with:
* Reduced moisture levels down to 900mm,
* Trunk and shoot growth with leaf area can be reduced by 80mm,
* Leaf nitrogen levels can be reduced by over 70mm,
* Production rates can also be reduced by 70mm.
Jordan LS (1981) Weeds affect citrus growth, physiology, yield, fruit quality. Proceedings of the International Society of Citriculture 2, Pages 481 to 483.
Numerous investigations around the world confirm
what producers know
It should also be understood that Neighbours may want this in mixed pastures for grazing animals meaning that boundary lines maybe a continual base for reinfestations. These can be more easily maintained if it is possible to:
* Continually rip along the fence line,
* Use the fence line as a wild life corridor inducing shade and other competitive understory crops.
The good news is that Cynodon dactylon appears to be highly allelopathic sensitive to Casuarina sp. and Allocasuarina sp. as; with the author’s records, the species is one of the first to decline into submission where these trees are prominent especially Cassuarina littoralis and Cassuarina Cunninghammii. So using trees in these families within the wildlife corridor of windbreak may prove to be very worthwhile and affective.
The seeds are usually distributed close to the parent plant and are not distributed by wind. When the plants grow near water, water currents may transport the seeds long distances. The other method of distribution noted by the author is that the plants require a carrier to transport them from one area to another. Often the plants suffer a bacterial growth during moist weather when copious quantities of seed are being produced. This bacteria makes the seeds somewhat sticky which then adhere to the coats of small rodent like animals or herbivores like wallabies and kangaroos which then deposit the seeds away from the parent plants.
It is important to understand the life history and behaviour of Cynodon dactylon before any real cost effective management plan can be incorporated on the farm, orchard or plantation.
* Its underground rhizomes can grow down to 750mm below the soils surface with most of the rhizome activity occurring in the upper 50mm to 75mm of soil and with 10mm of the rhizome activity occurring below 150mm of the surface,
* The growth rate of new plants sprouting from stem fragments (after cultivation) increases rapidly after four weeks, Muniyappa TV, et al. (1976) Growth pattern of Cynodon dactylon. Current Research, University of Agricultural Sciences, Bangalore 5 (9) Pages 152 to 153.
* Rhizomes can survive submersion in water for a long periods,
* Rhizomes that are buried deeper than 100mm have poor shooting emergence, vigour and reemergence, Phillips MC, Moaisi K (1993) Distribution of the rhizomes and roots of Cynodon dactylon in the soil profile and effect of depth of burial on regrowth of rhizome fragments. British Crop Protection Council’. Brighton, UK Pages 1167 to 1170.
* No new plants have been observed emerging from rhizomes buried
deeper than 400mm, Moreira I (1983) Biology of Bermuda grass (Cynodon dactylon (L.) Pers.). Revista de Biologia 12, Pages 519 to 528.
* It takes two weeks for new shoots to appear from rhizomes buried 50mm deep, and over a month from those buried 300mm deep, Moreira I (1983) Biology of bermudagrass (Cynodon dactylon (L.) Pers.). Revista de Biologia 12, Pages 519 to 528.
* New plants growing from rhizome fragments developed their own independent new rhizomes once they had ten leaves, Moreira I (1983) Biology of Bermuda grass (Cynodon dactylon (L.) Pers.). Revista de Biologia 12, Pages 519 to 528.
* 90mm of rhizome buds along the stem nodes died once the rhizomes were exposed to dry conditions for at least seven days or lost half of their original weight. Under higher humidity 90mm of buds died after two to four weeks exposure, Thomas PEL (1969) Effects of desiccation and temperature on survival of Cyperus esculentus tubers and Cynodon dactylon rhizomes. Weed Research 9 (1),Pages 1 to 8.
* Ploughing in winter then again in spring gave better control than ploughing twice in spring. The main benefit came from drying of exposed rhizomes after the winter ploughing then deep burial of 200mm by the spring ploughing, Phillips MC (1993) Use of tillage to control Cynodon dactylon under small-scale farming conditions. Crop Protection 1993 Volume 12 Number 4 12 (4), Pages 267 to 272.
* A higher proportion of nodes resprouted from smaller stem fragments with fewer nodes than those shoots emerged later, compared to larger fragments with more nodes, Fernandez ON (2003) Establishment of Cynodon dactylon from stolon and rhizome fragments. Weed Research 43 (2), Pages 130 to 138.
* Plants grown under shadier conditions produce stems with longer internodes, which result in fewer nodes per fragment after cultivation,
* With a 40mm reduction in light intensity from shading, the biomass production of couch is reduced by up to 75mm with a greater proportion of the plant resources and energy being recycled for leaf development rather than nodes and internodes, Guglielmini AC, Satorre EH (2002) Shading effects on spatial growth and biomass partitioning of Cynodon dactylon. Weed Research 42 (2), Pages 123 to 134.
Juraimi AS, Drennan DSH, Anuar N (2004) The effects of shading on the growth, development and partitioning of biomass in bermuda grass (Cynodon dactylon (L.) Journal of Biological Sciences 4 (6), Pages 756 to 762.
* Cultivation of couch depends on the soil type and density of the infestation. In heavy soils with dense growth a 300m deep chisel plough can spread internode fragments up to 30 meters. The same chisel plough only spread plants 3 meters where light infestations occurred on similar soils. In sandy soils with dense growth stem fragments were spread up to 60m. 50mm of fragments were dropped by the plough within 4m of their origin. Subsequent disc or tine harrow cultivation cut the stem fragments smaller but didn’t spread them further from the original patch. Only 5mm of the redistributed stem fragments survived. The survivors were partially buried during cultivation, Guglielmini AC, Satorre EH (2004) The effect of noninversion tillage and light availability on dispersal and spatial
growth of Cynodon dactylon. Weed Research 44 (5),Pages 366 to 374.
With the observations above remembering they have come from a variety of sources and a wide variety of climates and soil types, not all of them reflect all conditions on all farm operations and that the behaviour of couch specific locations in Australia may be different. They do however suggest that the following approaches may be of value in couch management:
* Overgrazing where possible is a very powerful tool in eradicating many problematic grasses and reeds like Cynodon dactylon. Pigs will root down quite deep while chickens will scratch the surfaces disrupting any broken pieces not allowing them the chance to reshoot and get a foothold. It is a chance to gain some additional income while eradicating a pest turning a expensive problem into a cash flow at the same time. (see above – Overgrazing)
* Because the bulk of the plant matter is contained in the top 150mm of the surface couch is highly vulnerable to shallow cultivation with follow up treatments being needed at opportune times to tackle the regrowth. Cultivation is best carried at depths of 120mm to 150mm in depth to expose as much of the material exposed on the surface or surface layers as possible during hot, dry periods
* Alternatively cultivation should aim to bury the stems as deeply as possible at 400mm or more in depth,
* Alternatively, cross disking the top 150mm to 200mm will cut the stems into smaller fragments with fewer nodes. A high proportion of these nodes would then sprout, depleting the fragments’ reserves more rapidly. Repeating the cross disking should be done at 14 to 21 day intervals in hot dry weather so the maximum impact is attained.
* Shading, the use of understory shrubs along with Cassuarina species and Allocassuarina species will eliminate the species along fence lines and wildlife corridors,
* Work from the outside towards the center of the infestations so that any fragments lost or dropped end up over existing infestations,
* Raise the implement and ensure it is clear of couch stems before proceeding into clear locations or retiring for the day,
* Repeating the above planned operations could take almost a year,
* Very low cutting or slashing of couch at least every two weeks to completely remove all regrowth reducing biomass after eight cuts by 99mm, and eliminated regrowth after 15 cuts is possible. The problem here is that soil compaction could be encountered, Horowitz M (1996) Bermuda grass (Cynodon dactylon): A history of the weed and its control in Israel. Phytoparasitica 24 (4), Pages 305 to 320.
* In tropical and subtropical locations; where permissible, a dense planting of Crotalaria juncea” will virtually eliminated” Cynodon dactylon in the first crop and provides vital nitrogen to the soil and huge quantities of up to 16 tonnes of biomass to the soil per hectare or a possible short term cash crop for fiber, Linares JC, et al. (2003) Effectiveness of annual and perennial cover crops in managing weeds in organic citrus. In ‘Organic Agriculture Symposium 2003’. (Center for Applied Rural Innovation, University of Nebraska, Lincoln Nebraska USA). http://cari.unl.edu/2003abstractpresentation/Scholbergmm20Proceedings.pdf
* A 60mm to 100mm deep mulch of rice straw and husks at 15 tonnes per hectare had reduced above ground dry matter production of couch by 96mm after six months. This should be applied during a hot dry period in spring immediately following a very low cut of the infestation. Abouziena HF, et al. (2008) Comparison of weed suppression and mandarin fruit yield and quality obtained with organic mulches, synthetic mulches, cultivation and glyphosate. HortScience 43 (3), Pages 795 to 799.
Secondary & Tertiary Pest Management
Looking at secondary and tertiary problems associated with invertebrate pests. Primary pests are those pests that directly attack the crops being grown as compared to those that follow the initial attack and often create the secondary or tertiary problems. As with Primary pests the producers is better off, first making themselves aware and comfortable with the Primary Pests section above.
In reality, relatively little action is taken against many primary pests by organic citrus growers in Australia. it is believed that Less than 10mm apply treatments for light brown apple moth, mealy bug or thrips, while the most troublesome primary pest, pink scale and white scale are only pursued by 30mm of organic citrus growers. RIRDC-Rural Industries Research and Development Corporation. David Madge
Email: rirdc@rirdc.gov.au. Internet: http://www.rirdc.gov.au
Sooty mould is a common problem associated with several sap feeding insects which include soft scales, mealybugs and aphids. Their faeces comprise of a sugary solution called honeydew. The sugary solution forms a sweet sticky coating on the leaves, twigs and fruits below which provides an ideal food source for a group of fungi known as sooty moulds. When the fungi produce their black spores, they develop an unsightly appearance referred to as ‘sooty mould’. While the sooty mould has no direct affect on the fruit quality it is seen as degrading quality by the public and reduces the value of the fruits on the fresh markets. It does interfere with photosynthesis of the plant which reduces the leaves ability to manufacture sugar and as a consequent will affect the overall production of the trees. Severe infestations of sooty mould will affect the tree’s healths.
The honeydew attracts sugar ants into trees seeking the source of the sugar. Ants disturb beneficial insects while harvesting the honeydew from aphids, scale insects and mealy bugs which in return disrupts the biological control of these herbivorous organisms.
To control sooty mould needs the producer to control the source of the problem that is the producers of the sugary solutions, the aphids, mealy bus or scale insects.
Viruses
The various viruses found amongst plants and crops are usually secondary related being transmitted by various vector carrying insects like aphids. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Galls
Galls are the secondary result of a parasitic wasp’s larval cycle. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Ants
Ants can be classified as both Primary and secondary pests. It is like which came first the chicken or the egg syndrome. They usually do not cause problems within themselves on the farm apart from being annoying and at times inflicting irritating stings, or fowl scents when contacted. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Rotting Fruit
Queensland Fruit Fly is the primary reason for most fruits becoming affected with fruit viruses, fungi, premature fruit drop or fruit fermenting on the tree. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Mealybugs
The feeding action of mites or mealy bugs results in discoloured surface scarring on fruits, except for the bud mite which distorts fruit, leaves and shoots. Most species prefer warm humid conditions and can multiply rapidly having up to 30 generations per year, especially in the more humid coastal districts. They may be responsible for a number of virus infections. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Spined citrus bug (SCB) Biprorulus bibax
Spined citrus bug distort leaves, cause wilting in new growth, fruit abortion and overall decline in the health of trees where major outbreaks occur. They may be responsible for a number of virus infections. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Thrips
Thrips have been known to devastate some crops which include the rose thrips and Gladiola thrips. The feeding habits of mites and thrips results in discoloured surface scarring on fruits, except for bud mite which causes distortion of fruit, leaves and shoots. Blemishes spotting of leaves and flowers shortening the cut life of flowers, stunting flowers and aborting of buds and fruit. Most species prefer warm humid conditions and can multiply rapidly with up to 30 generations per year especially in the more humid coastal districts. They are responsible for several known virus infections. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Snails
Snails and slugs mark fruit with blemishes, partially ring bark crops which can allow detrimental fungi to enter wounds close to the ground or reduces and or disrupt transport of essential nutrients from the roots and sugars from the leaves. See Primary pests above or chapter on Garden Pests for more details and recommended controls.
Physical limitations and remedies
Buffer zones/spray drift barriers
Buffer zones are those areas of land set aside to protect the farm from contamination sources like conventional cropping areas, manufacturing. The contamination is usually associated with spray drift, surface water flow from adjacent properties or soil movement during wind and water erosion. Buffer zones need to address:
* Areas adjacent to boundary fences or boundary lines and include an uncropped section or unsprayed parcel of land. They can include roads both external and internal and road reserves,
* A physical spray drift barrier such as natural vegetation, an artificial screen or windbreak,
* A portion of the property that excludes crops from organic certification or is left in a state for cover crops and recovering of materials for mulching,
* A property can be exempted from having a barrier if the adjacent property is certified organic.
Buffer zones can be used in various combinations to protect organic enterprises. The configuration of buffer zones is determined on site after accessing the properties geography, the adjoining properties uses, the risks of contamination from adjoining properties, the presence of a physical barriers in place to control spray, dust and water movement.
Chapter 33i
Vegetative barriers
Research indicates that the best type of living spray and dust barriers are those that are permeable to airflow, consisting of bushy trees with fine branches and leaves. Casuarina species and Allocassuarina species are ideal for this purpose. For a basic introduction to vegetative barriers I can be contacted any time for assistance.
These factors are extremely variable and considerations of spray equipment, chemical properties, wind speed and topography need to be addressed when designing a wind break or barrier. The Queensland Department of Natural Resources and Mines has developed a good guideline to work with, to minimize the risk of agricultural spray drift to adjacent residential areas. Their minimum requirement is a 40 metre wide buffer, comprised of a 20 metre wide band of trees and other plants bounded on each side by a 10 metre wide strip clear of vegetation (Figure 10‑1). Height of barrier trees should be at least double the height of the spray source – the higher the better. Significant protection from drift extends downwind only three to ten times the buffer height. Primary Industries Standing Committee (2002) Spray drift management: principles strategies and supporting information CSIRO Publishing, Collingwood Victoria, Report PISC (Formerly SCARM) report no. 82. http://www.publish.csiro.au/nid/18/pid/3452.htm
Management of Barrier Trees
Before establishing vegetative barriers, it is vital for growers to understand that the trees in the barrier themselves will require some management in the early years, usually in the form of irrigation, some nutrient input nutrition, hedging and possible root pruning. This is necessary to ensure that the barriers perform effectively and to minimize any negative impact they may have on the enterprises’ productivity through competition with the desired crops in the long term. These barriers can constitute part of the minimum land area needed to be placed aside for wildlife corridors.
Crop Area Buffer Zones
In many situations, especially where the properties are smaller and physical barriers cannot be established, areas of a crop may be designated as buffer zones. Because of their role in trapping contaminants. The buffer zones themselves are not included in the property’s organic certification and any fruit or small crop has to be harvested and handled separately from the certified crop and not be marketed as organic. This is a simple process of growing a different crop or fruit variety in this area.
External Buffers – Shared Management of Adjacent Land
Another method of reducing risk for the organic grower is to cooperate with his immediate neighbours and share management of a portion of the property that is adjacent to the certified land. If that adjacent land holder and manager carry out production in the zone refraining from using chemical inputs and use organically acceptable inputs then the risk of contamination of the certified property is reduced accordingly. This effectively shifts the buffer zone from the certified land to the adjoining property and avoids the need for the organic grower to harvest and sell a portion of their crop as “non organic.”
* The neighbour needs to agree to supply and use only organically acceptable sprays in the buffer area,
* The organic grower supplying the neighbour with acceptable sprays to use,
* The organic grower spraying the buffer area for the neighbour to avoid cross contamination of equipment,
* The organic grower pays for the difference in costs incurred to use organic products in the buffer zone.
My neighbours were happy to comform to this request in return for the supply of water to their water tanks when they ran dry.
If the adjacent land is a road verge, water channel power line or similar government property the organic grower could agree to manage noxious weeds, by slashing for example, in exchange for the council, road authority, power authority or water board avoiding herbicide use on that land. This approach requires a good level of trust and communication between the organic producer and their neighbours, and good communication and agreement with the relevant certifier. In our case we maintained the power easement for the power authority and they carried any maintenance with us in mind. An agreement was made that we would pay the additional pro rata cost for replacement of poles with labour in the future should the life of the poles be less than the surrounding poles. The power authority actually used the 3 poles on our property to trial a new oil based system. While the council was antagonistic initially after our win with eradicating the 2 noxious weeds on the property were more than happy to work in with us. Now that organics is a sizeable market and not in its infancy government officers are more willing to cooperate with producers instead of taking the hard line as they did in the pioneering days.
Legal Recourse
Laws are complex and if unwanted contamination impacts your organic enterprise in a negatively economic sense organic growers may have a case against the perpetrator of the contamination. Organic growers should familiarize themselves with the legalities of a contamination event. Three good places to start are:
* Your relevant organic certifier, the state agriculture department and the Environmental Defenders Office.
* The Australian Network of Environmental Defenders Offices Inc (2008) Australian Network of Environmental Defender’s Offices. [cited 2008 May]; Web site of the EDO – http://www.edo.org.au
* ACT Insurance Authority (2003) Risk management. (cited 2008 May), Provides useful descriptions of risk management & blank planning forms. http://www.treasury.act.gov.au/actia/Risk.htm
Pollution
Global warming and air pollution go hand in hand. It is the responsibility of the producer to lesson this impact as much as possible. Different machines emit different levels and different types of air pollution as they convert fossil and bio fuels to energy. The amount of pollution generated depends upon the engine condition and the type of fuel used. Less energy use means more profits. This can be achieved by:
* Practically, it is best to use the smallest engine available for the largest job on the farm ,
* If practical; buy more than one machine for the smaller tasks and one for the larger tasks – match the engine to the task,
* Use bio fuels instead of fossil fuels,
* Plan the work efficiently ahead of time. By slashing the inter rows when the grass is 200mm to 300mm in height instead of manicuring it will more than halve the fuel costs, wear and tear and maintenance of vehicles,
* Walk or use other means of transport where practical. It takes a minimum of 9 minutes to walk to the vehicle start it and drive away on an average farm. That’s 15 minutes walking to the destination,
* The utilization of humic acid can save hundreds of hours in irrigation which converts to thousands of dollars. Once our orchard was established and humic acid was at an optimum the use of irrigation had ceased. This was a saving of 480 hours a year on a small orchard of 1250 citrus trees saved almost 11,000,000 liters of water and 250 liters of diesel. This maybe small in the scheme of things but multiplied out by all the machinery and by all the organic farmers who care it adds up to a hell of a lot of fuel and water,
* Maintain the most efficient engine speed, according to the
manufacturer’s specifications.
Good engine maintenance is important to ensure efficiency, greater reliability and that emission levels are as low as possible.
Embodied Energy Efficiency EEE
Embodied Energy is the sum total of all the energy components required to manufacture an item which includes the raw materials, design work manufacture of moulds, transport etc. through to the recycling of the item at the end of its useful life. Another way of looking at EEE, is to look at the energy to make 1 kilogram of steel with an average recycle content. It takes 20.1mj and uses 1.3 kilogram’s of carbon Dioxide.
Water is another area which uses EEE. It takes an average of 1,600 cubic meters of water on average to produce one metric tonne of wheat. Some of this water is attained from rainfall and some maybe from irrigation. Citrus and rice are high water uses so when we export these products we are in fact exporting water EEE. In our case where we totally eliminated the use of irrigation water we actually reduced the EEE value of our produce immensely.
Waste
Nobody expects you to calculate the EEE on every item but to know it exists is acknowledgement that there are wastes in every corner of the farm that need to be addressed to maximize farm efficiencies and off farm EEE’s. Organic standards presently do not yet access wastes generated during crop production, responsibility still lies on the individual to be efficient in handling these issues. Waste management extrapolates the principles of organic agricultural production, in relation, not just to clean healthy food but extends to a clean healthy environment with minimal environmental impacts. Many organic farm inputs still have and still retain the potential to cause air, soil and water pollution if they are not be minimized further, handled or disposed of correctly. Therefore it stands that efficiency without the use of external inputs is the end objective for every producer.
Remember RRR – Reduce, Reuse, Recycle, with disposal being a last and least preferred option:
* Reduce waste by avoiding the introduction and use of materials
that will ultimately become waste. Purchase inputs in returnable drums, boxes or bags. Use biodegradable or long life tree guards to reduce the need to dispose of a short life, non biodegradable product. Look at ways to minimize damage and to extend the life of products needed around the farm and house,
* Reuse potential waste products wherever practical, including sale to other growers – plastic tree guards, stakes etc. Find alternative uses for old or disused products,
* Recycle everything that can be recycled – mulch or compost prunings, table scraps, garden waste. Use official recycling schemes for polypipe, machinery oil, tractor, batteries, tyres etc.
* Dispose of real wastes that cannot be substituted in an efficient and safe manner. Wastes such as batteries and oil that are to be recycled not dumped.
All addresses, phone numbers, emails and web sites were correct at the time of submission and will be upgraded as they are bought to our attention.
Organic industry regulation
Australian Quarantine and Inspection Service: AQIS
Organic Program
Postal: GPO Box 858, CANBERRA ACT 2601
Phone: 02 6272 3928
Email: organic@aqis.gov.au
National Standard for Organic and Bio-dynamic
Produce:
Internet: <http://www.daff.gov.au>
AQIS-approved organic certification organisations:
Internet: <http://www.daff.gov.au>
Organic Organizations
Peak international industry body
International Federation of Organic Agriculture
Movements (IFOAM)
Postal: Charles-de-Gaulle-Str. 5, 53113
Bonn – Germany
Phone: +49 228 926 50-10
Fax: +49 228 926 50-99
Email: headoffice@ifoam.org
Internet: http://www.ifoam.org
Organic Certifying Organizations
Peak Australian industry body
Organic Federation of Australia (OFA)
Postal: PO Box 369, BELLINGEN NSW 2454
Phone: 1300 657435
Email: info@ofa.org.au
Internet: <www.ofa.org.au/>
AUS-QUAL Limited
Postal: PO Box 3403
TINGALPA DC QLD 4173
Phone: 07 3361 9200
Fax: 07 3361 9222
Email:
Internet: http://www.ausqual.com.au/
Australian Certified Organic
Postal: PO Box 530
CHERMSIDE QLD 4032
Phone: 07 3350 5706
Fax: 07 3350 5996
Email:
Internet: http://www.australianorganic.com.au/
Bio-Dynamic Research Institute
Postal: PO POWELLTOWN VIC 3797
Phone: 03 5966 7333
Fax: 03 5966 7433
National Association for Sustainable Agriculture
Australia
Postal: PO Box 768 STIRLING SA 5152
Phone: 08 8370 8455
Fax: 08 8370 8381
Email: enquiries@nasaa.com.au
Internet: http://www.nasaa.com.au/
Organic Food Chain
Postal: PO Box 2390
TOOWOOMBA QLD 4350
Phone: 07 4637 2600
Fax: 07 4696 7689
Email: ofc@organicfoodchain.com.au
Internet: http://www.organicfoodchain.com.au/
Safe Food Production Queensland
Postal: PO Box 440 SPRING HILL QLD 4004
Phone: 07 3253 9800
Fax: 07 3253 9810
Email: info@safefood.qld.gov.au
Internet: http://www.safefood.qld.gov.au/index.php
Tasmanian Organic-dynamic Producers
Postal: PO Box 13
CAMPBELL TOWN TAS 7210
Phone: 03 6381 2004
Fax: 03 6381 2008
Email: info@tasorganicdynamic.com.au
Citrus Industry Representation
Australian Citrus Growers
Postal: PO Box 5091, MILDURA VIC 3502
Phone: 03 5023 6333
Email: admin@australiancitrusgrowers.com
Internet: <http://www.australiancitrusgrowers.com.
au>
Murray Valley Citrus Board
Postal: PO Box 1384, MILDURA VIC 3502
Phone: 03 5051 0500
Fax: 03 5021 1905
Email: executive@mvcitrus.org.au
Internet: http://www.mvcitrus.org.au/
Riverina Citrus
Postal: PO Box 1432, GRIFFITH NSW 2680
Phone: 02 6962 4333
Fax: 02 6964 2285
Email: admin@riverinacitrus.com.au
Internet: <http://riverinacitrus.com.au/>
Pest & Disease Diagnostic Services
Horticulture Diagnostic Service
South Australian Research and Development Institute
Postal: GPO Box 397, Adelaide SA 5001
Phone: 08 8303 9562
Fax: 08 8303 9303
Internet: <http://www.sardi.sa.gov.au/dhtml/ss/
section.php?sectID=1097&tempID=1>
Plant Health & Plant Pathology Unit
Department of Primary Industries, Water and
Environment
Postal: 13 St. Johns Avenue, New Town TAS 7008
Phone: 03 6233 6833
Fax: 03 6228 5123
Internet: <http://www.dpiwe.tas.gov.au/inter.nsf/
Services/CPAS-5MS9DV>
Soil & Plant Analysis Services
Australian Perry Agricultural Laboratory
Postal: Box 327, Magill S.A. 5072
Phone: 08 8332 0199
Fax: 08 8361 2715
Email: info@apal.com.au
Internet: http://www.apal.com.au
Soil analysis and interpretation using the Albrecht
approach
Soil Foodweb Inc.
Postal: 1 Crawford Rd., East Lismore NSW 2480
Phone: 02 6622 5150
Fax: 02 6622 5170
Email: contact@soilfoodweb.com.au
Internet: <www.soilfoodweb.com.au>
Soil, compost and compost tea microbial analyses
SWEP Analytical Laboratories
Postal: Box 583, Noble Park VIC 3174
Phone: 03 9701 6007
Fax: 03 9701 5712
Email: services@swep.com.au
Internet: http://www.swep.com.au
Soil and plant analysis and interpretation using an
alternative Albrecht-style approach
Biological Control Suppliers
Australasian Biological Control
The umbrella body for producers of biological control
agents in Australia and New Zealand.
Internet: http://www.goodbugs.org.au/
Biological Services
Postal: Box 501, Loxton SA 5333
Phone: 08 8584 6977
Fax: 08 8584 5057
Email: info@biologicalservices.com.au
Internet: www.biologicalservices.com.au
Parasitic wasps, predatory mites, pheromone traps
Bugs for Bugs
Postal: Bowen Street, Mundubbera Qld 4626
Phone: 07 4165 4663
Fax: 07 4165 4626
Email: info@bugsforbugs.com.au
Internet: <www.bugsforbugs.com.au>
Parasitic wasps, predatory ladybirds, lacewings and
mites, fruit fly control products
Other Organic Suppliers
Entosol (Australia) Pty Ltd
Postal: Box 28, Roselands NSW 2196
Phone: 02 9758 4552
Fax: 02 9758 4882
Email: sales@entosol.com.au
Internet: www.entosol.com.au
Pheromone sticky traps for lightbrown apple moth,
Qfly and Medfly
Organic Crop Protectants
Postal: 42 Halloran St., Lilyfield NSW 2040
Phone: 02 9810 4566 or 1800 634 204
Email: info@ocp.com.au
Fax: 02 9810 4674
Internet: <www.ocp.com.au/>
Organically certified crop protection products
including horticultural oils and Spinosad fruit fly bait
spray
Wild May Fruit Fly Attractant & traps
Phone: 07 3349 5283
Email: wildmay@powerup.com.au
Internet: http://www.wildmay.com/
Wild May Qfly wet traps
Nutri-Tech Solutions
Phone: 07 5472 9900
Email: info@nutri-tech.com.au
Internet: <http://www.nutri-tech.com.au/>
Fly Bye Fruit Fly Lure for Qfly wet traps
Australian Pesticides and Veterinary Medicines
Authority (APVMA)
Postal: Box 6182, Kingston ACT 2604
Phone: 02 6210 4700
Internet: <http://www.apvma.gov.au/>
Organic Wholesale Outlets in Australia
United Organics – Ross Cowling
109 Randolph St, Rocklea QLD 4106
Phone: +61 (07) 3278 5997
Eco Farms
167 Parramatta road Homebush NSW
Phone: +61 (02) 8284 0070
E-mail: retail@ecofarms.com.au
Eco Farms
17 Mephan St, Footscray VIC 3011
Phone: +61 (03) 9318 3055
Organic Retails Outlets in Australia
Your local Produce Store Proprietor
Email: <_____________________________________>
Phone Number
Personal Contacts
Name:
Email: <_____________________________________>
Phone Number
Name:
Email: <_____________________________________>
Phone Number
Name:
Email: <_____________________________________>
Phone Number
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