To go, or not to go, 'organic'?

 The case for an organic approach is made out either in terms of a desire to care for the land or to care for the ultimate consumer.

What is meant by an 'organic' approach to farming is pretty variable. Compounds with identical molecular formulas may be regarded as organic when synthesized by a plant and not if synthesised in a factory. Pyrethroids produced by the petroleum industry from ancient organic material or distilled by a different industrial organization from a flower are a case in point. From my point of view as a farmer, there is no distinction to be made between the chemicals derived from either source and I will purchase the cheaper version. As a spray plant operator I am no safer using one form rather than the other. I respect growers who are chasing certification but in some cases I see them pursuing questionable objectives or working with one hand tied behind their backs, without a very good reason to do so.
 

For thousands of years farmers and gardeners have observed a positive response to the application of organic materials to growing plants. Mulch it, manure it, water it and watch it grow. This simple observation engenders a faith in things 'organic' which is about as reputable and respectable as motherhood.

The case for an organic approach is made out either in terms of a desire to care for the land or to care for the ultimate consumer. Cultivation is preferred over herbicide use to control weeds.
The chicken raising industry has used hormones to promote growth and a diet of antibiotics is required to counter infection in environments where chickens are penned, relatively immobile, and in close contact with spoiled feed and excrement. Consumers pick up these additives in chicken meat. However, the chicken industry is not typical of all agriculture.

Modern grain farming in relatively dry climates uses herbicides for weed control. This avoids destructive cultivation. Seed is drilled into the compost of the last crop. This is a highly responsible form of farming that conserves soil fertility and minimises the need for non organic fertilizer inputs.

Herbicides are by far the most used chemical tools in cropping. The organic approach to farming runs into a big problem when a hardy weed like kikuyu appears. It can be a case of use it or lose the utility of the land.

 

Maintaining soil fertility

The key to maintaining soil fertility in any agricultural system is maintaining the balance between what is removed from the system (via harvesting or burning or blowing away) and what is returned to the soil as plant debris. Nutrients to support plant growth originate in organic matter, the product of past growth, and also via slow demineralization of the native rock. Deep rooted plants - including weeds - break up the soil and build up organic matter levels at depth as the plants die. Worms and other soil organisms feed at or close to the surface and may burrow deeply chasing soil moisture in drier times. Their population relates directly to their food supply - decaying plant material. A soil kept absolutely free of annual grass or weed growth by harvesting or herbicide will soon deteriorate. This is similar to a cropping regime where the straw is harvested along with the grain and the stubble burnt. Even worse is a heavily grazed paddock where plants never produce the root growth to sustain a decent top. The soil will have an extremely thin organic enriched zone and relatively impenetrable subsoil. The surfacel may become water repellent and the first rains carry what little organic matter and manure lies on the surface into the valley bottoms. Unless there is lots of vegetation on the slopes and in the valley bottoms to take up nutrient the stream may become toxic with algal growth with dreadful consequences for marine life within it.

A monitoring programme by our local catchment group has revealed that the stream that enters our Karridale vineyard leaves the property with less nutrient than it has when it enters. This is because our mulch layer of slashed grass between and around the vines provides effective catchment for water and detritus that would otherwise run off. Secondly, the tea tree that grows in the valley bottoms is also a highly effective nutrient trap. We tolerate it despite the protection it provides for the birds.

Viticulture that uses a total herbicide approach to weed control is thoroughly irresponsible. When combined with harvesting of the crop and the removal of vine prunings the system spirals into decline

In vineyards, overly controlling weed growth can reduce the capacity of the soil to germinate seeds and support plant growth. This then becomes a diminishing system. The loss of organic matter will reduce future cropping levels. That's why we have a trashy vineyard with lots of cut grass and even uncut grass sitting on the surface. This appearance is based upon our understanding of the cycle of nature, built on organics.

One must achieve a nice balance between preventing the volunteer weeds strangling the vines and controlling them to the point where a crop is produced that will pay costs. The optimum state may not please the careful suburban gardener or the anally retentive types who prefer to see a complete absence of competing plant material, dead or alive, and likes rows of carefully clipped vine foliage.

One must achieve a nice balance between preventing the volunteer weeds strangling the vines and controlling them to the point where a crop is produced that will pay costs. The optimum state may not please the careful suburban gardener or the anally retentive types who prefer to see a complete absence of competing plant material, dead or alive, and likes rows of carefully clipped vine foliage.

The sustainable situation is the one where organic matter levels in the soil are stable or increasing. In striking this balance a herbicide can be a very useful tool to keep weeds from growing up through the vines. Herbicide use can be a cost effective and responsible solution. The alternative of cultivating between and under the vines is energy intensive, requiring several passes, and is destructive of organic material and soil moisture. 

On the other hand viticulture that uses a total herbicide approach to weed control is thoroughly irresponsible. When combined with harvesting of the crop and the removal of vine prunings the system spirals into decline. A row width factor enters here: Vines occupy little of the spatial environment and utilize a lower proportion of solar energy on wide row plantings. The wide row vineyard will suffer organic matter depletion if it is kept weed free.

Used sparingly, herbicide is preferable to a cultivation regime and is a very responsible method of weed control. Energy consumption is lower, implements are simpler and cheaper, the speed of operation is faster, and the result less deleterious in its effect on soil life and organic matter levels. More of the soil (particularly the topsoil inhabited by grasses) is available for a longer period to sustain the vine. These comments apply to the sort of Mediterranean dry summer where weeds naturally die off in the summer months. In a moist summer environment where weed competition is more sustained, a greater level of intervention may be required.

The question of contamination and toxicity

What is the point of producing a crop that has no danger of carrying potentially harmful chemical inputs if our first step in processing the crop is to add a toxic substance? That is how I look at the use of sulphur dioxide in winemaking. Sulphur dioxide is commonly used in all winemaking, organic or otherwise.

Finally lets recognise that plants produce an abundance of toxic substances for their own defence. Indiscriminate feeding on these plants can have terminal consequences. American vines successfully defend themselves from Phylloxera and Odium that will devastate the European vine. Decaying leaves of the grapevine smother and poison early weed growth in Autumn. Many arid zone plants use this mechanism to take out competitors.
Humans select carefully those plant materials that will be consumed and dilute or prepare appropriately those which can be toxic. In seeking medicine to alleviate human ailments, herbal remedies, their use based on generations of observation, often with little in the way of a written record, are available for use quite free of the rigorous trailing demanded of the products of the modern chemical industry. We should recognize that we have been running this particular gauntlet for a very long time.

There is no evidence yet that herbicides move from the soil into the crop and the food chain. Any downside to their use is associated with heavy and continual use that begins to reduce the growth of the vines themselves. The loss is product foregone rather than damage to the food chain.

This is in clear contrast to the situation with pesticides. The potential for movement of pesticides like DDT, organochlorines and organophosphates into the food chain is well documented. There is also the very direct danger to the operator or the bystander, including animals that graze a crop soon after it is sprayed. However, a balanced view recognizes the difficulties that are faced and the practicalities of the situation.
Exotics like the African Black beetle and the African Garden Weevil are as devastating in the Australian environment as the Eucalypt is in the African situation. The Koala, introduced to Kangaroo Island in South Australia is devastating the eucalypts to the point where culling, transportation or sterilization is necessary. These are extraordinarily difficult situations to deal with. Our choices are very limited. In many a situation of this sort a viable 'organic approach' is simply not available.

Our approach

Intelligent farming cares for pest predators rather than inadvertently wiping them out with the primary target. Intelligent farming uses strange inputs in the most conservative possible fashion.

Our Mediterranean climate with it's dry summers is a low input, relatively relaxed, and clean farming system. We stop spraying fungicides about the end of December and the berries are still tiny at that time. They have two to three months to lose that spray residue before the crop is picked. Elemental sulphur, the main tool used to control Powdery Mildew and mite growth in organic and regular farming volatilizes into the atmosphere, and therefore disappears with time and temperature. This is the typical vineyard stink that you get when you walk into a vineyard in spring time. By the end of summer when the grapes are picked it is gone. It is in the springtime when the pests tend to emerge. By midsummer, when the grasses are dry, the pests have gone and the disease pressure falls away. Later in Autumn, we pick a clean crop. In vegetable production, by contrast, the crop can be sprayed when quite mature, withholding periods for spraying may be just a few days, and the whole cycle is much shorter.

In winemaking the growth of an enormous biomass of yeast and bacteria and finally the sedimentation processes that occurs before the wine is bottled all tend to diminish the level of any residues that come in on the grapes. Fermentation is a cleansing process. Nobody washes grapes prior to fermentation. Nobody separates out the dust, spiders, the beetles and the ants.

I see little evidence to support the suggestion that a strictly organic approach to viticulture, in our Mediterranean climate, is likely to produce superior outcomes for the environment, producers or consumers. There is much to learn from those who teach an organic path and much to avoid in the silver bullet approach of the chemical industry quick fix. In farming as in life, a healthy scepticism is required. One of my uncles was a Pharmacist, but he never took medicines, believed in lots of exercise, hard work and good home prepared food.

Organic vineyards are no protection against the worst offenders to our health: Contamination after harvest

When the crop is harvested and treated with a toxic chemical to prevent the growth of moulds, bacteria or insects, something that might be done to any crop regardless of its origin, we cannot pretend that it is any better for being produced on an organic farm. Grain is stored in silos and can be readily attacked by birds, rodents, insects, moulds and a panoply of fermentative and degradative processes that afflict organic materials. We can use chemicals or we can use gases to conserve grain. Carbon dioxide is the more responsible approach.

The situation in winemaking is similar. What is the point of producing a crop that has no danger of carrying potentially harmful chemical inputs if our first step in processing the crop is to add a toxic substance? That is how I look at the use of sulphur dioxide in winemaking. It is possible produce superior wines using very little or none at all. The armoury of tools at a wine makers disposal to achieve that end include hand harvesting, inert gases, temperature control and judicious filtration. Oxidation and bacterial growth - the chief reasons for the use of sulphur dioxide - can be avoided by the careful winemaker using other tools where possible.

When we know that undesirable growth of microorganisms begins as soon as the juice of the berry is exposed, the choice of a mechanical harvesting system is very much a second best option. Sulphur dioxide usage is the only remedy available in that situation to slow the growth of organisms. Sulphur dioxide hardens the palate of a wine. The advantages for wine makers lie in reducing its use because a more palatable wine will result. I believe that, as we discover that we can do a better job with different tools we will rely less and less on this chemical. Hand harvesting is part of that recipe.

The World Health Organization has guidelines for ingestion of sulphur dioxide. These guidelines can be exceeded by drinking wine with levels of sulphur dioxide permitted by law. This is not speculation designed to frighten or persuade consumers who know very little about the reality of farming or winemaking. This is a much more substantive issue than anything that relates to the treatment of the crop in the field. It is a therefore a very sensitive issue for the 'organic movement'.

Suming Up

All of these comments I will qualify by saying that we are constantly being surprised by what we don't know and never guessed. We never anticipated that plants that were genetically modified to be immune to Glyphosphate, would cross with other plants to produce a super weed. It is happening in the Canadian Prairies. Farmers are constantly facing new challenges. The world is still young. Every continent has its specialised species of plants and animals. When you take a species from one place where it is held in check by a bundle of competitors who have evolved with it over a thousand years and drop it into a new environment where there is nothing that wants to eat it, farmers face massive problems. If the farmer cannot call upon the chemical industry to supply a product to keep the new arrival in check he is in real trouble. However, farmers must always look to working with nature rather than against it. Intelligent farming cares for pest predators rather than inadvertently wiping them out with the primary target. Intelligent farming uses strange inputs in the most conservative possible fashion.

There is no better worker for the gardener and farmer than the humble earthworm. He lives on organic matter. If we look after him our plants will thrive and better resist disease. The best fertilizers are the slow release form that is closest to organic materials in its release pattern. We know very little about how a plant gathers what it needs from the soil. This is still a realm where magic, mystery and funny ideas compete with hard science. Superphosphate demonstrably boosts plant growth and Australian soils are chronically deficient in that element. More plant material on and in the ground means more earthworms, better soil structure, greater levels of organic matter at depth, better infiltration of rainfall and better prospects for the next crop. Other, less concentrated sources of phosphate release the desired nutrient more slowly and simply represent a slower payoff for the dollar spent. That may be a good choice in many situations but not necessarily all.

Postscript April 2010

We went to a lot of trouble to run ducks to control snails, and chooks and guinea fowl to control grasshoppers. We surrounded the vineyard with a high fence to keep out foxes. But the eagles gave us a hard time, and people wouldn't close the gates, and the foxes climbed over anyway. So we have up and started buying snail pellets. We chose pellets that were harmless to the birds. The snails multiplied. But large flocks of ibis appeared and cleaned out the snails! Springs became wetter and the grasshopper eggs rotted in the ground. So, there is a happy ending to this story.

In the late 90's the South African Garden weevil came to eat the young vines but we hated spraying so we tolerated some damage. As the years rolled on something else came to eat the weevil. Don't know what it is but it's doing a good job. The weevil is everywhere but the numbers are small. So, this too is a story with a happy ending.

As the vineyard gets older the soil is improving. The depth of organic matter is gradually increasing. The wines ferment with ease, showing a good nutrient level in the grapes. We must be doing something right.

In the summer the vineyard is covered with grass debris like the forest floor and this keeps the soil cool, conserving moisture. If a fire comes we are lost but in the meantime looking after the soil demands that we take that risk. This is the chief element of our organic approach to viticulture.