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Ecology and Agriculture

Jaydev Jana |

One thing is sure; the earth is more cultivated and developed now than ever before; there is more farming but fewer forests, swamps are drying up and cities are springing up on an unprecedented scale.We have become a burden to our planet. Resources are becoming scarce and soon nature will no longer be able to satisfy our needs.

~ Quintus Septimius Tertullianus, 200 BC

The agricultural system has depended mainly on internal resources, recycling of organic matter, built-in-biological control mechanisms, and natural rainfall patterns. Its yields were modest but stable. Production was safeguarded by growing more than one crop or variety in a field as insurance against pest outbreaks or severe weather. Inputs of nitrogen, the most essential plant nutrient, were gained by rotating major field crops with legumes.

The cultivation of different types of crops over the years on the same land also suppressed insects, weeds, and diseases by effectively breaking the lifecycles of these pests. This type of farming linking agriculture to ecology, commonly called ecology- farming, was so strong that signs of environmental degradation were seldom evident.

However, humanity’s longest struggle has been the ongoing battle, waged on different fronts, to feed itself. To ensure food security for the growing population, agriculture has been modernized with the use of machines, a large quantity of fuels, pesticides, herbicides, synthetic fertilizers and chemicals. This facilitated the Green Revolution that has conveyed the impression that agriculture is a miracle of food production.

But as agricultural modernization progressed, the ecology-farming linkage was often threatened. This is where the real puzzle crops up. While food production is threatened by environmental changes caused by industries, today’s modern agricultural systems are also the single largest source of human-induced environmental changes. The litany of ‘ecological diseases’ is quite clear.

There has been an erosion of the soil which is gradually losing its fertility. Precious water supplies are being squandered, rangeland overgrazed, forests destroyed, groundwater (GW) polluted and fisheries overexploited. The outcome of indiscriminate use of pesticides has been the increasing human morbidity and mortality while, at the same time, pests are becoming resistant and escaping from natural control.

Indiscriminate application of synthetic fertilizers has been polluting water bodies and destroying ozone layers. Other agricultural pollutants have the potential for damage on a much larger scale. In other words, the agricultural systems themselves are a source of threat to future production.

Hence, modern agriculture is both the culprit and victim in relation to global pollution. The importance of biological diversity to suppress insects, weeds and diseases cannot be overemphasized. Diversity of crops and the soil below the ground provides protection against the vagaries of the weather as well as outbreaks of diseases or the damage caused by pests.

But the grand tradition of modern agriculture to ‘simplify’ the biodiversity has led to the slow change of crop diversity over the years. The process accelerated with the Green Revolution in the 1960s. The complex natural ecology was then replaced by ecology that involved monoculture or near monocultures worldwide, where the same crop (usually corn, wheat, or rice) is grown year after year in the same field, or very simple rotations are used (such as corn-soybeancorn- soyabean).

From the ecological perspective, there are many disadvantages of monoculture. Normally in a natural ecosystem, the cycles of nutrients, energy, water, and waste remain open rather than closed. But monoculture finds it difficult to recycle nutrients even though a substantial amount of crop residues and manure are produced in the farms. As a result, agricultural waste becomes a liability rather than a resource.

This apart, the problem with monoculture is that if insects like the crop, they find a huge food supply in one place. Conversely, a field containing a variety of plants does not offer a large quantity of food for the pest. So it will not get the nutrients it needs to survive and thrive. The rampant use of pesticides and herbicides, under the adage, ‘if little is good, a lot more will be better’ has played havoc with human life and other forms as well.

Nearly 90 per cent of pesticides never target the pests they are meant to but end up contaminating air, soil and water… eventually entering the food chain as slow poison. Of course, the extent to which pesticides and herbicides persist depends on their unique chemistry, which affects absorption.

For instance, DDT or BHC are so persistent that they are still found in water, soil, food and human blood even though their use was banned many years back. Those pesticides have undergone bio-magnifications. Even though it is claimed that ‘new’ organophosphorus pesticides (OPs) are less persistent in the environment, it is not mentioned that low doses of these pesticides are far more toxic than the previous varieties. Since OPs are widely used at present, people get re-exposed.

Moreover, systemic pesticides enter the metabolism of the plants and cannot easily be eliminated. Their residues remain in the soil after harvesting and even get transferred to the next crop. Soil contamination can alter microbial processes and increase the plant uptake of the chemicals. It can also cause toxicity to soil organisms. Pesticides also enter the food chain, and eventually reach the dining table. Studies have linked pesticides to a wide range of health hazards ~ from infertility to cancer.

As pesticides are used again and again they do not take too long before the targeted weeds, pests or even other pests become resistant. This keep the farmers on a ‘pesticide treadmill’ as the other pesticides lose their effectiveness and new ones need to be used. Pesticides are increasingly being used in Punjab, Haryana, Andhra Pradesh, Uttar Pradesh and Maharashtra. Soil health is tremendously important for cultivable crops.

This can be achieved by appropriate and efficient use of synthetic fertilizers along with highyield seed varieties and other favourable agronomic conditions. But the bountiful harvests created at least in part through the use of synthetic fertilizers have associated environmental costs. Two main reasons of environmental pollution are the wasteful application of synthetic fertilizers and inefficient spraying on crops.

Clearly, the present food system is neither beneficiall for the farmers nor the environment. Nor for that matter does it ensure an adequate food supply for the people. To radically transform agriculture, the appropriate technology should be adopted.

We should emphasize the importance of relatively small-scale, local production in agriculture, using technology appropriate to a given set of social/historical/ ecological conditions with the intuitive appeal ~ ‘The right thing in the right place at the right time.’

It bears recall that the Nobel Peace laureate, Dr. Norman Borlaug, in his acceptance speech had called for a ‘vast army’ in the battle against hunger. Agriculture in the 21st century represents a noble application of our collective human ingenuity.

The writer is a retired IAS officer