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| Tuesday, 6 July 2004 |
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Chemical farming - the perils spiral by Preethi Sirimanne
Chemical fertilizers are in fact growth stimulants that produce rapid increase in yields. However, studies reveal that plants growing in highly chemicalized soil lose their natural defensive mechanisms to fight against diseases. Further, since chemicals unlike organic material do not break down or decay, they finally contaminate the ground water as well as the rivers. Chemical companies highly recommend urea as a nitrogen release fertilizer. But there are evidences which indicate the adverse effects of this chemical fertilizer. Andy Lopez writes in 'The Invisible Gardener' that there is a clear difference between an organic source of nitrogen and chemically prepared one. A fundamental problem with urea based products is how they are available to plants. Natural sources provide plants with nitrogen as they need it. In contrast, chemical nitrogen such as urea is absorbed by the plants in very large amounts whether they need it or not. As urea contains a high percentage of nitrogen, excessive feeding kills the good bacteria and leave behind a mutated form of bad bacteria which attack the plants. Due to the imbalance between good and bad bacteria, the plant roots cannot function as they should. Subsequently, they get accustomed to chemical fertilizer and become susceptible to diseases and cannot survive without the help of pesticides. Pesticides The World Health Organisation annually counts 2 million pesticide poisonings and says that even 200,000 people per year die. Yet, the ubiquitous advertisements made by chemical companies camouflage risks, deny the negative effects of pesticides, and claim that pesticides have no harmful effect, if they are used properly. The distinguished scientist and veteran researcher in insect control Professor Robert van den Bosch revealed a number of cases involving diseases and death in connection to pesticides that were properly used. He writes in his book 'The pesticide conspiracy': "Today the pesticide treadmill spins more widely than ever. We use twice as much insecticide as in 1962, there are more insect species of pest status than ever before, insect control costs have skyrocketed, and insecticide impact on the environment is the worst in history. There is, then, a pro-pesticide mafia, whose members operate much in the manner of those in its Italian namesake. Crop scientists knew that certain chemicals in pesticides are hazardous. Yet, it took several years until DDT was banned. Reports indicated that DDT poisoned the nervous system of birds, reduced their hormone levels causing thin eggshells and this in turn caused the disappearance of varieties of birds. Mosquitoes that were sprayed with DDT developed behavioural and metabolic resistance to chemicals. What happens when insects are sprayed is that some die but others survive and appear in a mutated form. In other words, pesticides cause genetic changes in the population of insects. Herbicides that are sprayed to kill weeds are equally damaging as they reduce the food supply to insectivorous birds. Once specific insect varieties are reduced, the ecosystem loses its balance in stability and flexibility. In addition, residues of chemicals end up in rivers and streams poisoning algae and aquatic plants from which many aquatic organisms and fish rely upon as food. Organic farming Many people realizing the damages of chemical fertilizers, insecticides, herbicides and fungicides are now changing their mode of farming to organic farming. Fertile soil is the farmers capital. Therefore, to achieve optimum results farmers are now trying to understand the physical and biological properties of the soil. The study of soil fertility, compost making and discovering new kinds of organic material has already brought immense benefits. The most vital part of the soil is the humus, which serves as reservoir of plant nutrients. In one teaspoon of rich organic soil there are some 600 million to 1 billion beneficial microbes from 15,000 species. In contrast, in a teaspoon of chemically treated soil there are only 100 microbes living. The soil organisms fungi, microbes, earthworms and other almost invisible species - create an intricate microscopic ecosystem, which is termed as the Soil Food Web by soil scientists. The Soil Food Web in its effort to serve plants not only prepares food but also stores the food in its own Food Bank. The soil microbes metabolize organic material by breaking down soil minerals, releasing potassium, phosphorus, magnesium, calcium and iron. Specific bacteria make and release plant growth hormones, which stimulate root growth. Microbes also have the unique ability to change the inorganic matter to organic matter, so that plants can absorb them. Earthworms play a significant role in soil fertility. With their enzymes, they split complex material into simple molecules in such a way that they neutralize acids during their digestion and deliver the best form of humus. Earthworms also enhance the growth of beneficial bacteria providing optimum conditions such as moisture, aeration and phosphates. To increase the quality of soil, organic farmers use compost made of grass, weeds, vegetable peelings, dead leaves and apply a layer of activator which is usually made of powdered animal and fish bones. Researchers have found that algae, guano (droppings of seabird like penguins and bats), crab shells, feathers, chicken bones, fish bones and scales, as well as remains of shredded sugar cane, cotton seed, and soybean are excellent manure for plants. Natural control An extraordinary experiment carried out by the International Centre of Insect Physiology and Ecology (ICIPE) in Africa developed a push-pull-system that provided excellent results to control pests and insects through natural biological means. ICIPE scientists invited the local farmers to give information about the food that the insect stemborer consumed. They then took selected grass varieties and planted them outside the maize fields to attract stemborers. At the same time molasses grass and silver leaf were planted within the fields as the stemborers cannot bear their smell. This technique functioned superbly and the crop losses could be reduced by 80 per cent. African scientists reported how they controlled the spotted stemborer: A wasp Cotesia flavipes cameron, which tracks down the stemborer larvae deep inside the stem and lays its eggs into the pest. These hatch and consume the stemborer from within. After careful testing, the wasp was released on three sites in Kenya. The wasps are now well established and they not only go for the spotted stemborer, but for three other stemborer varieties. Successful experiments such as these demonstrate how helpful it is for the scientists to work together with traditional farmers in solving insect and pest problems. Nature demands harmony. Whoever tries to destroy the ecological equilibrium and induces methods that go against the laws of nature in the name of profit is sure to be surprised by natures revolt. |
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Produced by Lake House |
Cheerleaders of the modern agriculture technology have misled the
farmers into believing that the usage of chemicals in agriculture is an
advanced form of scientific formula which effectively increases yields and
reduces crop losses. Today, millions of farmers feel that chemical
companies have deceived and misguided them with tainted and
non-transparent studies in the name of high productive farming technology.
