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You can have organic or preservative free, but not together.
Definitions 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. Should it be? 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. 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. For the background on the chicken industry see 'Organic food and the crook chook' page 25 Australian Financial Review Weekend Nov 17th-18th 2001 www.afr.com However, the chicken industry is not typical of all agriculture. Modern grain farming in relatively dry climates uses herbicides (weed killers) for weed control, avoids destructive cultivation and direct drills seed into the trash of the last crop. This is a responsible form of farming that conserves soil fertility and minimises the need for non organic inputs. Herbicides are by far the most used chemical tools in cropping. Despite the use of insecticides to conserve grain in silos there is no evidence that Australian cereal based foods exhibit harmful levels of residues from the inputs of fertilizer (promotes growth), weedicide, fungicide (kills fungi) or insecticide used on farms. However, the clearing of low rainfall areas has resulted in rising water tables and a disastrous loss of landscape to salt. An organic approach to wheat cultivation will not help the latter situation. The answer appears to be anything that will lower the water table including the growing of deep rooted native plants and deep drainage.
Maintaining soil fertility In vineyards, too conscientious a control of annual 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. The most desirable state is where a nice balance is created between preventing the volunteer weeds strangling the vines and controlling them to the point where a crop is produced that will pay costs and yield a profit. This will not be a pretty scene to the eye of a suburban gardener or a traditional farmer who prefers to see a complete absence of competing plant material dead or alive. The most sustainable situation is the one where organic matter levels in the soil are stable or increasing, and do so across the entire soil surface. In striking this balance a herbicide can be a very useful tool to prevent weeds using valuable soil moisture. Herbicide use can be a highly responsible and cost effective pursuit. The alternative of cultivating between and under the vines is energy intensive, requiring several passes and destructive of organic material and soil moisture. Difficult weeds like couch and Kikuee that grow into the summer are almost impossible to eradicate without the aid of specialized herbicides. 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 at low levels, 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 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 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. Furthermore 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 ensue 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 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 skepticism 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 tucker.
Contamination after harvest When we know that undesirable growth of microorganisms begins as soon as the juice of the berry is exposed a mechanical harvesting system that produces juice in the vineyard is a poor choice. Sulphur dioxide usage is the only remedy available in that situation to slow the growth of these organisms and we therefore lock ourselves into it's use. 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 legislation. 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'.
Perspective 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 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. Common sense dictates that organic farmers should have a more rigorous standard for the use of sulphur dioxide in winemaking than they do. Any other stance smacks of religion rather than science. Erl Happ February 2002 |
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