Organic Agriculture Association Inc.

FAQ's - Organic (If you cannot find an answer, submit a question or contact the OAA)

The why and how of organic food production
Pest, disease and weed management
Soil management
Managing livestock
The why and how of organic food production
How is food grown organically?

Farmers and gardeners learn that to grow organically they must work with nature and not try to dominate it.

Organic growers diversify their farms, moving away from the vast monocultures of agro-business.

Organic growers use a wide variety of techniques such as crop rotations, green manures, rock minerals, compost, biological inoculants, animal manures, soil aeration, and mulching.

The whole thrust of organic agriculture is to FEED SOILS - NOT PLANTS.


Feeding soils increases soil biological life and improves soil structure - leading to a highly resilient system and long-term HIGH SOIL FERTILITY.


Crops become healthy and vigorous; production increases, pest and diseases in plants and animals diminish, and problems which may occur can be treated with low-toxic natural remedies.


Organic Growers do not use water-soluble chemical fertilisers because while they may increase production, their use eventually destroys soil structure and fertility.

Run-off from these fertilisers pollutes groundwater, rivers and lakes.

Chemical fertilisers produce large, sickly plants - and thus animals, both subject to attack by insects and disease.

Farmers are then forced to buy expensive pesticides and drugs in an attempt to maintain production.

Residues are passed on through the food chain, causing a wide range of health problems.

Production from organic farms may be slightly lower, and use about 10% more labor, but is at least as profitable as chemical farms, as costs of organic farming are lower.

And products are SAFE TO EAT and the land can go on producing this way indefinitely.


"A Non-Polluting, Regenerative, Sustainable Agriculture"

Is organic food better for my health?

Yes. Even minute amounts of some pesticides are harmful to health. Non-organic produce, when tested, usually shows residues of several different pesticides. Certified organic produce is free of pesticides, though some contamination from agricultural chemicals in the environment is possible. Nitrate levels are lower because soluble nitrate fertilisers are not permitted in organic farming, which means plants can select the amount of nitrate they need, instead of being forced to take it up whenever they take up water. The levels of antioxidants in organic produce is higher; these antioxidants are produced by the plant to defend itself from pests and diseases, a process suppressed by chemical usage. Lastly, organic food usually has higher levels of calcium, magnesium and trace elements (copper, zinc, manganese, cobalt, selenium), though this is not consistent in all organic produce, and some non-organic produce has high levels, depending in both cases on how much attention the producer pays to balanced soil fertility.

Can organic farming feed the world?

Yes. There is research to show this is the case. The world already produces enough food to feed 10 billion people (12.5 billion by some calculations). Much is wasted (about a third, according to the FAO). Some is used to make biofuels, or is fed to livestock, which is a very inefficient way to produce meat. Hunger is not the result of insufficient food – it has social, economic and political causes, not production causes.

The evidence shows that initially, after conversion to organic methods, yields drop, but as soil fertility and organic matter increases, yields often overtake those before conversion, and particularly so in bad seasons when organic systems demonstrate greater resilience. The argument that we need genetic modification and greater fertiliser use to feed the world has no sound basis. What is necessary is to change economic and social conditions so everyone has the right to food.

See: Organic Agriculture and Food Security, published by IFOAM, 2020 https://www.ifoam.bio/organic-agriculture-food-security

How long does it take to obtain organic certification?

In most cases it takes three years from sending in application form and an Organic Management Plan. After the first inspection, the farm has one year of pre-certification. This is followed by two years in conversion, during which the produce can be sold as Organic In Conversion. Some certifiers allow full certification in one year, if the producer can show that no synthetic pesticides or fertilises have been used in the previous several years.

How can I gain organic certification? What is the process? What does it cost?
The first step is to obtain a copy of the organic standards, which specify which inputs and practices are allowed and which are prohibited. Every country in the world has its set of organic standards, which do vary. If exporting, it is necessary to abide by the standards of the export destination. The standards are freely available on the internet. Two of the main certifying organisations in Australia are NASAA (National Association for Sustainable Agriculture Australia) and Australian Certified Organic. 

The second step, after determining that you can abide by the standards, is to put in an application to one of the certifying organisations and complete an organic management plan (which can also be downloaded).

The organisation will send out an inspector to check on inputs and practices, and if you pass, your farm will enter pre-certification. The next annual inspection will put you in Organic in Conversion for two years – many markets accept this status. After the third year the farm can be certified as Organic. In some circumstances, if you are able to prove that no non-allowed inputs have been used for some time before the certifying application, the period can be shortened. 

Costs in Australia are about $1,000 per year, plus a levy once sales pass $40,000 of 1%. Check with the certifying organisation for up to date figures.
Is there increased risk of bacterial contamination of food grown organically because of the use of manure and compost?

No. Manure and compost are placed around the plant, not on it, and usually before the crop is sown. Human manure is not allowed under organic standards. Bacterial contamination is one of the chief concerns of Global GAP (Good Agricultural Practices) certification, while the much more serious risk of chemical contamination is ignored. Global GAP prohibits the inclusion of livestock in orchards, including chickens, because of risk, yet allows pesticides. Animals are an important part of ecosystems, and in orchards are used to control pests and diseases, control weeds, and add fertility. Animals are allowed under organic standards, even encouraged. The unreasonable fear of biological contamination is used by the anti-organic pro-pesticide lobby to denigrate organics.

Can I grow foods successfully without any chemical inputs?

Yes, but not without management changes. The millions of organic farms in the world prove it can be done. It requires greater knowledge of soil biology, soil fertility, ecology, and pest and disease and predator interactions. There is a vast amount of information available in books, courses, the internet, and the resources of the Organic Agriculture Association. Organic growing is not as simple as buying a pesticide or fertiliser from a shop.

Does the failure of large scale organic conversion in Sri Lanka mean that organics is not viable, as claimed by the chemical industry?

No. It shows that adequate planning that involves farmers and consumers, providing training, research and the development of organic input industries (such as large scale compost making, biological control products and vermiculture) is necessary for success, and inadequate planning the cause of failure. Large scale organic conversions have been very successful in the Indian state of Sikkim, in Cuba, and in several municipalities in the Philippines. Without planning and education, conversion on any scale is unlikely to succeed.

How can I obtain organic seeds?

Organic standards require the use of certified organic planting material, which includes seeds, seedlings and fruit trees. Availability is sometimes limited. If the grower can produce evidence that organic planting material of the desired species and variety is not available, a derogation may be issued for a limited time. However, such seeds must not have been treated with a fungicide. In the longer term, growers can save their own seeds to ensure they comply with the requirements of the standards. There are several companies selling organic seeds and seedlings.

Are hybrid crop varieties allowed in organics?

Yes, but there can be some drawbacks. Firstly, seeds of hybrids cannot be saved to produce a new generation – they will either not germinate, or will be too variable, often of lower quality. Secondly, hybrid seeds are usually bred for high yield, but this yield is dependent on chemical fertilisers which makes them more susceptible to pests and disease. High yield often comes with lower hardiness. Thirdly, hybrid seeds are usually more expensive. Some non-hybrid crop varieties have high yield with hardiness.

Can I obtain organic certification if residues of DDT or heavy metals are found in the soil?
Some farmland has been treated with DDT and/or other related organo-chloride pesticides in the past. Examples are dieldrin, lindane, endosulfan, all of which are no longer permitted in farming. DDT and dieldrin were commonly used on fruit and vegetable crops, particularly apples and potatoes. Lindane was sometimes added to superphosphate to control pasture grubs and crickets. Endosulfan’s main use was for cotton. Arsenic was a common component of sheep dips, and cadmium a contaminant of superphosphate. Lead arsenate was used as an insecticide before the development of DDT. Zinc levels can be vastly excessive in urban areas and former industrial land, usually from galvanised iron roofing. Organo-chlorides are very persistent in soil – DDT can still be found 50 years after it was last used. Heavy metals never bio-degrade. 

In filling out an organic management plan the farmer must identify any possible contamination. The inspector will take soil samples for testing. Presence of contaminants does not necessarily preclude certification under Australian standards, but may do so under US standards. Under Australian standards the produce can be tested for residues instead, as many crops do not take up the contaminants. However, the farmer may be prevented from growing certain crops like carrots, or livestock which can consume soil either deliberately or via grass roots. Heavily contaminated areas, such as around sheep dips, can be excluded from certification, well fenced off from livestock access.
How can I prevent spray drift from a non-organic neighbouring farm?
There must be a barrier, a buffer zone, between the certified farm and non-organic farms, of at least 5 metres. The barrier should be a dense planting of trees and shrubs. This will also serve as wind protection and habitat for birds, insects and other wildlife. The barrier might not be fully protective, as some pesticides volatise and come down in rain many kilometres from where they were applied. 

Organic farmers need to maintain good relations with neighbours and ask that the wind not be blowing towards the farm boundary when the neighbour sprays. Legal action is possible against the neighbour, but should be avoided if possible in order not to create additional animosity, and because culpability can be difficult to prove in court.

The organic farmer is obliged to report spray drift to the certifier, which may order soil and produce tests.
Is organic farming/gardening more productive?

Often yields are a bit lower, especially in the short term, but not necessarily so. In low rainfall seasons organic yields are generally higher because of better organic matter levels in the soil that holds moisture and improves water infiltration. The weight of some produce at harvest time is not a reliable indicator of yield, as non-organic produce contains a higher percentage of water, which is lost in storage (for potatoes, for example, immediately after harvest non-organic crops can weigh more, but a month or two later the reverse happens).

Why is organic produce more expensive?

Non-organic produce is cheap because the externalities are not part of the selling price – the damage to health and the environment. These costs are paid by society as a whole. Organic produce does not incur these externalities, so should be more expensive. Sometimes it is said that “you cannot afford not to buy organic produce”, because of the harm non-organic produce does to human health.

 

Sometimes organic produce costs more to grow. This could be because of higher labour requirements, especially for weed management; sometimes because of lower yields; for chicken and pork because intensive housing is not permitted; and the cost of certification. Sometimes retailers add higher margins, partly to compensate for unsold produce, but mainly because they believe the market will bear it.

What are the differences between Organics and Biodynamics?

Biodynamics is an organic system, so any produce labelled as biodynamic is also organic. Biodynamics, though, is extra, requiring the use of the biodynamic preparations 500 and 501. BD 500 is made by burying a cow’s horn filled with cow manure in the ground for 6 months, then mixing it with water in a certain way to aerate it and bring the microbes into life. It is sprayed on the ground. BD 501 is crushed rock high in silica prepared in a similar way and sprayed on to foliage. BD 500 activates soil biological life to release locked-up minerals; BD 500 increases the ability of the plant to protect itself from pests and diseases. There are several other BD preparations that are added to compost heaps.

Is Regenerative Agriculture organic?

It can be, but it is not necessarily so. There are no standards for regenerative agriculture, so the methods used vary. Organic agriculture on the other hand has a certification system to guarantee a certain standard of inputs and practices.

Pest, disease and weed management
Are biological pesticides permitted under organic standards?

Yes, as long as they are not genetically modified (such as the bacterial treatment used by fruit tree nurseries to prevent crown gall). However, they should only be used in a limited way, as they can cause undesirable changes to the soil biological community and can harm natural predators. For example, the fungus Trichoderma is often used to treat soil and plant leaf diseases, but used excessively it will also attack mycorrhizal fungi. Some other commonly available biopesticides include Beauveria, Metarhizium, Bacillus thuringiensis (Bt), and Pseudomonas fluorescens. They either counteract pathogenic fungi or cause fatal disease for insects.

Are there any organic herbicides that I can use instead of Roundup?

Yes, there are alternatives, but they tend to be expensive and of limited effectiveness. They are made from the oils of various plants: pine, orange peel, pelargonium. You can make your own using double strength vinegar, or industrial grade acetic acid. Flame weeders and steam weeders are also available. All work best on young annual weeds. They kill off the tops of perennials but rarely affect the root system, so the weeds regrow. Flame weeders are not designed to burn, but to boil the sap. They can be handheld tools using a single gas jet and small gas bottle, or a large machine. Steam weeders are more involved, which makes them more expensive, but with no fire risk: they need a water tank, compressor and heat source. Most organic farmers use weeding implements and machines; there are some which do minimum soil disturbance. Mulching is also a valuable tool, as bare soil always invites weeds.

What causes mature avocado and chestnut trees to decline and die?

The most likely cause is Phytophthora, a root rotting fungus that can proliferate in poorly drained soil. Both avocadoes and chestnuts need a deep, well-drained soil. A mulch of woody materials around the trees, but not touching the trunk, provides a good habitat for beneficial fungi that counteract the Phytophthora as the wood decomposes. Compost is also valuable. To save an ill tree, an application of Trichoderma fungus could be effective.

How can I attract beneficial insects to my garden?
Firstly, do not poison them with pesticides.

Most beneficial insects require pollen and/or nectar from flowers in order to reproduce. Plant long-flowering plants around the edges of the production area, either perennial shrubs or herbaceous annuals. Anything that flowers can be used, including naturally growing weeds (flatweeds and dandelions for example). The flowers of members of the carrot family are particularly good – fennel, coriander, parsnip, carrot, parsley – as they have flat easily accessible crucibles of nectar. Perennial daisies (eg. Marguerites) flower for much of the year.
How can I control codling moth in apples?

There are several methods, which can be used together. Chooks under the trees catch the grubs as they migrate to the soil to pupate. A band of cardboard around the trunk captures some of the grubs as they crawl down the trunk to the ground – it should be used from 6 weeks after flowering till the harvest is finished, changed every week. A sticky band around the trunk catches the female moths as they flutter up the trunk to lay eggs on the developing apple. There are pheromone traps on sale that are placed around the orchard to confuse or catch the males as they search for a mate. There are many natural predators – ground beetles, spiders and earwigs. 

How can I control fruit fly?

There are several species of fruit fly. I eastern Australia it is Queensland fruit fly; in the west it is Mediterranean. Other species include oriental fruit fly, mango fly, and melon fly. Management is similar for all species.

Pheromones are available. These are the scents given off usually be females to attract a male for reproduction. They can be used to attract males to a trap, or to confuse the male by saturating the orchard in the scent.

There are various easily made baits to attract females. Place the bait in one litre plastic bottles with holes drilled in the neck to allow entry but not exit, and hang in trees, replacing at least weekly in the danger period. Here are some recipes:

1.  Mix 2 grams of brewer’s yeast and 150 grams of sugar in 500 ml water.

2.  Cut ripe banana peel into pieces, mix with sugar, flour & water

3.  Mix 5 ml vanilla essence, 20 ml ammonia, half a cup of sugar, 2 litres water

4.  Mixture of sugar, soy sauce, ammonia in water

Some other techniques include running chickens in an orchard to catch the larvae as the prepare to pupate in the soil, and when they emerge as flies; and covering fruit with bags, either purchased or home made with newspaper. Infected fruit should not be buried because the larvae will not be killed and will re-emerge as flies.

How can I control capeweed?

Capeweed, Arctotheca calendula, is a weed from South Africa that can turn paddocks into a sea of yellow in spring, suppressing other species and compromising animal health because of its high nitrate content and low magnesium.

Capeweed is purely a product of bare soil in autumn. No matter how many capeweed seeds are in the soil, or blow in, very little capeweed will germinate unless it has space. The task then is to maintain ground cover, whether living or dead. This can be done by rotational grazing systems, where livestock are moved on while some uneaten pasture remains, and do not return till good regrowth occurs.

Low cover of capeweed is not a problem, up to 5-10%. It has nutrient value and is palatable, as long as there are plenty of other species for nutrient balance.

Are there any herbicides that organic farms can use?

Yes, but they can be expensive and not very effective on well established weeds, particularly perennials with strong root systems or underground runners (couch, kikuyu). They are not systemic (that is, entering into the whole plant sap system as many chemical herbicides do) so only affect the above ground parts without killing the root system. They can be very effective on young weeds. The products on sale are based on various plant oils: citrus peel oil, pine oil, pelargonium oil. Vinegar can be effective, though household vinegar does not have enough acetic acid to work really well – double strength vinegar or industrial acetic acid are better (avoid eye contact!).

Can copper-based fungicides be used in organic orchards?

Yes, in a limited way. Bordeaux (copper sulphate mixed with hydrated lime) and copper hydroxide can be used, but not copper oxychloride. Orchardists need to periodically test the soil for copper levels. While copper is an essential nutrient, once the amount in the soil exceeds 5 parts per million (or milligrams per kilogram), beneficial soil fungi and earthworms start to be supressed. Excess copper also suppresses other trace elements, particularly molybdenum which is essential for legume plants to produce nitrate. After 25 years of copper fungicide use, some orchards show up to 25 ppm copper. 

Does companion planting work?

Some combinations work in some environments. There is no universal guarantee. However, some combinations are shown to be valuable. A legume interplanted in non-legumes increases nitrogen availability for the non-legume. Carrots or peas help protect brassicas from diamond backed moth and cabbage white butterfly infestations, partly by repulsion, partly by disguise. Basil protects tomatoes and capsicums from fruit fly. Chilli protects onions and leeks from aphids. Carrot or peas protect cabbages from aphids. 

Why do pests and diseases attack plants?

Pest and disease attack is governed by soil fertility, biodiversity and the use of pesticides and soluble fertilisers. Almost all pesticides, including those organic growers can use, affect beneficial as well as harmful organisms. Chemical fertilisers (and excess manure) weaken a plant’s cell walls, enabling ready entry to pests and disease. Pesticides weaken the ability of the plant to produce pest and disease repelling substances in its leaves. In general, pesticides and soluble fertilisers worsen a pest or disease problem, and create new ones. There are some excellent examples of yields increasing when pesticide use is reduced. Monoculture greatly increases the likelihood of pest and disease attack.

Soil management
Why is urea not allowed in organic farming?

While urea is a natural component of urine, the urea used in agriculture is manufactured using large amounts of gas. It is highly soluble, which means the plant cannot select how much it needs. It turns to nitrate in the leaves. Some volatises, turning into nitrous oxide, a powerful greenhouse gas. Some leaches into the water table or washes off the soil into waterways. It is the main cause of high nitrate levels in some rivers and in ground water supplies. 

How can I tell if my legumes are properly doing their job of increasing soil nitrogen?

Legumes have an association with Rhizobium bacteria, which form nodules on the plant roots and convert atmospheric nitrogen, which plants cannot use, into nitrate, which they can. To do this successfully there needs to be a suitable pH (between 5.5 and 7.5 approximately), good drainage, and sufficient molybdenum, cobalt and boron in the soil. Soluble nitrate and phosphate fertilisers, and some herbicides, interfere with the process. There are several species of Rhizobium, specific to particular groups of legumes. They might not be present in the soil. They can be added, either coated on seeds (as with lucerne) or bought as a preparation to be added to the soil or to seeds.

To check for Rhizobium activity, carefully dig up a legume and check for nodules. Cut open a nodule with a very sharp knife or razor blade. The inside should be pink. If it is green no nitrogen is being produced. If it is brown the process has finished or never started.

What are Effective Micro-organisms? EM?

EM is a commercially made microbial preparation used to improve soil biology, counteract pathogens, and aid decomposition of organic matter. It can be used for cleaning produce before sale too.The microbes are mainly photosynthesising bacteria, lactic acid bacteria, yeasts, actinomycetes and fermenting fungi, which naturally occur in soil and water. EM was developed by Teruo Higa in Okinawa in the 1980s. Bokashi is an example of EM. The evidence for the effectiveness of EM is poor – several trials have found no benefits.

How do I make small scale good quality compost teas?
Compost tea is made by pumping air through water in which a bag of compost is suspended for a day or two days, usually with some kind of microbial food source added to the water (molasses, flour, fish emulsion). The aeration rapidly breeds up the microbial population in the compost bag. It can be made in a 20 litre container. An air compressor is required, and a perforated hose that is coiled around the inside of the container. Before starting, you should obtain full directions (there is plenty of information on the internet), as things can go wrong. 

Is it worthwhile making, considering the effort needed? There is conflicting opinion. Some people claim good results for plant growth and for disease control; others have stopped making it because they cannot see improvements.
Is it OK to use paper in compost making and worm farming?

Yes, but not glossy coloured paper, as the dyes are often based on heavy metals. Coloured newsprint is OK. Whatever the source, the paper needs to be shredded so that it does not pack down, resisting moisture and microbial activity. Paper is a high carbon material, useful for balancing the high nitrogen content of food scraps, lawn clippings and manure.

Where can I get phosphorus from if I can’t use superphosphate, MAP or DAP?
Because soluble phosphorus from fertilisers becomes locked up with aluminium and iron in acidic soils, and calcium in alkaline soils, and superphosphate has been used for more than 100 years on most Australian agricultural soils, there are vast amounts in the soil that only biological activity can release. This biological activity includes mycorrhizal fungi and several other species of fungi and bacteria. Some plants have unique abilities to access locked up phosphorus that other plants do not have – they can be grown as a green manure crop. As they decompose, their phosphorus content becomes available to crops. Species include buckwheat, white lupins and chickpeas. 

There are some non-renewable sources of phosphorus: rock phosphate and guano. Other good sources include manure, compost and blood and bone meal. Compost increases available phosphorus above what it actually contains, as the microbes in compost release locked-up phosphorus from the soil.
Which is better for the soil, lime or dolomite?
It depends on the soil. Limestone is calcium carbonate; dolomite is a compound of calcium and magnesium carbonate, commonly containing about 28% calcium and 14% magnesium, though this varies with the source. Both contribute to the raising of the soil pH. 

The ratio of calcium to magnesium is very important in the soil, as it largely determines the soil structure. The ratio should be about 6:1, six parts calcium to 1 part magnesium. A soil that is sticky when wet and hard and cracked when dry contains too much magnesium. Adding dolomite to that soil will make it worse. Sandy soils need more magnesium to hold the particles together. Only a soil lab test will provide an accurate picture. Both potassium and sodium also affect soil pH and the availability of calcium and magnesium. Animal and human health is compromised by insufficient magnesium.
Can I use too much compost or manure on the garden?

Yes. Soil tests on some organic gardens where large amounts of manure or compost have been used show vastly excess potassium and phosphorus levels. Excess potassium promotes weediness and makes some vegetables taste bitter, because it suppresses calcium and magnesium. A sure sign is prolific growth of stinging nettles.

Can I use manure from non-organic cattle?

Yes, but it must be hot composted first, to break down any antibiotics or drenches that the cattle might have been treated with. The compost temperature must be at least 55 degrees for three days. The same applies for manure from other non-organic animals, and indeed for any other organic material from a non-certified source (straw, hay, etc).

What is the role of mycorrhizal fungi in soils?
Most species of plants form an association with at least one species of mycorrhizal fungus. The fungus invades the plant roots without harming the plant. The plant feeds it, and the mycorrhiza releases locked up phosphorus and other nutrients from the soil for the plant to use. The fungal threads extend deeper and wider than the plant roots, thereby effectively extending the area the plant can access minerals and water from by many times. A by-product is the production of a stable form of carbon called glomalin.

Few crop plants do not have an association with mycorrhiza. Beets and brassicas are the majority. However, most of the other plants without an association become severe weeds in degraded soil, as they have the advantage over beneficial plants by being able to thrive without mycorrhiza. They include the following pant families: Chenopodiaceae (eg. fat hen, clammy goosefoot); Amaranthaceae (eg. Prince of Wales feather, red root amaranth); Polygonaceae (eg. wireweed, docks, sorrel, three-cornered jack); Brassicaceae (eg. wild mustard, radish, turnip, shepherd’s purse, peppercress); Juncaceae (eg. spiny rush, toadrush); Caryophyllaceae (eg. chickweed); Scrophulariaceae (eg. twiggy mullein, creeping speedwell); Commelinaceae (eg. wandering Jew); Cyperaceae (eg. Cyperus – nut grass, umbrella sedge).

There are two broad groups of mycorrhiza, those that associate with forest trees, often producing toadstools above ground, and those associated with herbaceous plants and small trees; these do not produce toadstools.
What is Korean Natural Farming?

This is an organic farming system developed by Cho Han-kyu in the 1960s. It is based in the use of various substances fermented with IMOs (Indigenous Micro-organisms) to enhance plant health and growth, similar to EM. It is a low input system where everything is recycled. 

How can I obtain clean garden soil for my raised beds?

The quality of soil from garden supply outlets varies from impoverished acidic sands to rich composted mixtures.  It is not  unknown to identify contaminates like plastic, or far worse, even in products certified by Australian standards separate from organic.

Any soil can be improved, but some require many years. Clays can be improved with lime, mulch and plant root exudates that will gradually turn clay into topsoil. Sands require very large amounts of organic matter; they are usually deficient in many essential nutrients and have no structure; they could be water repellent; and might pack down very hard. Spent mushroom compost can help with structure, though is usually low in nutrients. If you are not making your own compost, Coco peat is another option, which sometimes has additional nutrients added, so as always, read the label. Commercial compost varies in quality, depending on the origin of the materials and the composting method. Products made from composted chicken litter, and certified organic, can be relied on as additions to soil. With this in mind, sometimes soil can be utilised from your own land.

 

Soils can be tested for contaminants at low cost under a program to assist home gardeners. It is called GardenSafe for Victorian residents, VegeSafe for other areas of Australia, and SoilSafe Aotearoa for New Zealanders. Information is available at https://www.360dustanalysis.com/

How do I keep my organic soil in good condition year by year?
Here are a few guidelines.

Keep the soil covered, by living plants or mulch, to improve water penetration and retention, feed the microbes, help control weeds, and prevent oxidation of soil carbon.

Rotate crops, using a legume about every third crop (beans, peas, clover, vetch) to restore nitrogen.

Return crop residues and weeds to the soil, either as mulch or lightly dug in. 

Use compost or worm castings between each crop. 

Do not dig unless it is necessary to remove strong rooted weeds like couch and kikuyu, because digging disturbs fungal networks and earthworms, and causes some carbon loss.
What damage does soil tillage and digging do?

Carbon is lost, partly because it is exposed to the air and oxidises (turns to carbon dioxide), and partly because certain bacteria are stimulated that start feeding on previously stable organic matter. The networks of various fungi are broken. Some earthworms are damaged. Over some years a hard pan develops at the depth to which the plough, or spade, reaches. However, if herbicides are used in place of tillage, gains of no-till are negated.

How are green manure crops used to increase soil fertility?

Green manure crops are a good way of improving soil structure and fertility. They are grown for 2-3 months, then are destroyed by ploughing in lightly or mulching at the time they start flowering, which is peak nutrition. Trials have found they are very effective. It is a good idea to use more than one species, including at least one legume and a grass (wheat, rye, barley, ryegrass). 

How does gypsum work as a clay breaker? Are their limitations on its use?

Some stiff clays have very high levels of either magnesium or sodium or both, which impedes water and root penetration. Stickiness is a sign of magnesium excess, while cloudiness in water indicates excess sodium. The theory of applying gypsum, which is calcium sulphate, is that the magnesium and sodium will bond with the sulphate and pass out of the soil, and the calcium will stay. However, this does not happen in some soils. If the calcium level is low, it is the calcium that leaves the soil. Such soils will respond better to limestone than gypsum. Gypsum is suppressive of soil fungi at applications over 500 kg/ha.

Is there benefit to adding a biological stimulant to my compost heap?

It is not essential, as organic material often contains sufficient decomposing bacteria and fungi on its surface, and in manure. Microbes are also in the air. The addition of a biostimulant can speed up the composting process. Suitable biostimulants include biodynamic preparations, EM (Effective Microbes), several proprietary products, and simply a little matured compost from a previous heap.

When should a compost heap be turned?

When the temperature gets to 55 degrees. If it exceeds 65 degrees, there is the risk of combustion because of the alcohol produced, or the formation of charcoal. The temperate can be tested by making a hole in the heap, inserting a thermometer on a string, and pulling it out after 15 minutes. Another way is to insert your arm – if you can’t leave it there the compost is too hot. A metal bar can be used – if too hot to touch when removed, compost needs to be turned. When turning, the outside of the heap is placed in the centre, so all parts are processed equally. It is likely that more water will be needed as the heap is being turned.

Are seaweed and fish fertilisers allowed in organics?

Yes, but check the ingredients to make sure they are not boosted by a chemical fertiliser such as urea.

My tomatoes flower, but I get very few fruits. What can I do about this?

There are several possible causes: lack of pollinators, hot weather (over 35 degrees), lack of potassium, or excess nitrate that produces prolific growth.

Is there a difference between compost worms and earthworms?

Yes. Earthworms process soil, obtaining much of their nutrition from soil micro-organisms, while compost worms feed directly on organic matter. Compost worms can survive in soil as long as there is mulch on the soil surface and sufficient moisture. They thrive on the same kind of materials that are used to make compost. There are three main species: Lumbricus rubellus (red worm), Eisenia fetida (tiger worm), and Perionyx excavatus (blue worm, which is suitable for tropical climates).

How can soil be tested so I can find out what minerals are there and which are not?
There are some simple tests anyone can do to help determine the mineral status, particularly the balance between calcium and magnesium, excess sodium, salinity and pH. A test for plant sap sugars using a refractometer can tell if the plant is getting the full quota of nutrients, but will not reliably tell if something is missing. The colour of leaves and the presence of particular weeds can also be used as indicators.

However, accurate determination is done by a laboratory test. There are several companies that do this test. Always avoid those connected to a fertiliser company. Testing is done for plant-available minerals; there are commonly greater reserves in the soil that plants cannot get without the aid of good populations and diversity of soil microbes. Chemical farming suppresses these organisms, which means only the plant available minerals mean anything. Over time, organically managed soils enable some of the reserves in the soil to be released. It is worthwhile getting a total test done, which includes the reserves that are not currently accessible to plants.

Each laboratory will specify how to take samples. Generally, what the labs require is a bag of soil taken to a depth of 10 cm from many sites on the farm and amalgamated. A soil sampling tool makes this easy. 

There are limitations on the value of lab testing. Samples are only done for the topsoil, while plant roots can go much deeper; the availability of minerals changes due to temperature and moisture levels – this is especially the case with nitrogen availability, but many others are affected too; labs have some different testing methods and different recommendations. Generally, though, a lab test is worthwhile. Cost is about $150. 

A standard test includes organic matter, pH, the major nutrients and 5 trace elements, plus the cation exchange capacity and the calcium-magnesium ratio. Other tests are optional extra – total nutrients (available and unavailable to the plant), other trace elements, heavy metals, pesticide residues. Labs often provide recommendations for fertiliser application to rectify deficiencies. Some labs are more used to dealing with organic farmers and accommodating their needs than others; they include Environmental Analysis Laboratory (Lismore NSW), SWEP (in Melbourne), and APAL (Australian Perry Agricultural Laboratory, in Adelaide).
Can I make organic compost if I use waste from bought non-organic inputs?

Yes, if hot composted. The compost temperature must rise above 55 degrees for at least 3 days, and again after turning that mixes the outside ingredients with the rest so that all parts of the heap reach this temperature. The heating process destroys weed seeds, antibiotics, growth hormones and most pesticides. However, it does not destroy heavy metals, so organic farmers must have sound information about the origin of the material. If only material from an organic farm is used then there is no need for a hot composting system, though the process will be much slower and weed seeds will survive.

How may I measure the amount of microbes in my soil?

Some soil laboratories have methods of doing it (for examples those of the Soil Food Web). SWEP in Melbourne also has a method. They give readings for functionality groups, not individual species of which there could be hundreds of thousands. A simple test kit that measures carbon dioxide respiration from soil is another method. Measuring the length of time it takes to decompose a cotton cloth inserted into the soil is a simple method, but it is necessary to have a standard to compare with.

Managing livestock
Are vaccinations allowed for organic livestock?

Under Australian organic standards they are permitted with a veterinary declaration that the particular disease is prevalent in the district, or is required by law. Under US standards, on the other hand, they are required.

Can antibiotics be used to treat sick animals?

If antibiotics are essential for the treatment of a particular case, the priority is the health of the animal. However, that animal is no longer organic. It must be held for a period in a quarantine paddock away from the rest of the flock or herd of at least 3 weeks or three times the withholding period of that medicine. Then the animal can be returned, remaining out of organic status for the rest of its life. Organic farmers must keep accurate records of every treated animal and maintain its identification (by ear tag, for example).

How does rotational grazing increase soil carbon?

Rotational grazing where large numbers of stock feed in a small area for 1-3 days and do not return till that pasture has completely recovered, which might take from 2 months up to 12 months, increases soil carbon and feed quality by two ways. The longer grass is better able to photosynthesise. Some of this extra carbohydrate is exuded through the roots to support soil microbes, up to 40% in grasses. Mycorrhizal fungi convert some of this carbon to a very stable form of humus. The mycorrhiza and other soil microbes in return for the carbohydrate increase the availability of previously unavailable nutrients, particularly phosphorus.

The second mechanism for increasing soil carbon is the death of a proportion of the plant roots after grazing, and the trampling of uneaten grass into the topsoil. This form of carbon is less stable than that formed by the mycorrhiza.

When pasture is perpetually grazed short there is limited opportunity for photosynthesising, so there is little available to exude through the roots. Plant roots are short and the plants are unable to withstand dry conditions.

I have seen my cows chewing bones. What does this mean?

It is a reliable sign of phosphorus deficiency. A short term solution is to provide finely ground rock phosphate in containers for the cows to choose instead of bones.

My chooks have messy backsides and I suspect intestinal worms. How can they be controlled?

A simple method is to put chopped up garlic into the drinking water. Chooks will peck it out to treat themselves. Pumpkin seeds, carrots, mulberry leaves, black wattle leaves can be included in the diet, chopped up and added to normal rations.

How can I treat pink eye in cattle without using antibiotics?

Pink eye is a bacterial infection in the eye that causes weeping and cloudiness. It is spread by flies and dust to susceptible animals. Sometimes it is caused by a grass seed in the corner of the eye. The grass seed must be removed, carefully without damaging the eye. The eye in both cases is treated with Vitamin A drops or cod liver oil, and covered with a cloth patch for a few days because it will be very sensitive to sunlight. Normally an animal obtains sufficient Vitamin A from green grass, but this is not often available all the year.

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