Short essay on the Effects of Modern Agriculture



Historically, man as hunter-gatherer could not affect the environment because he was using the natural population of animals and plants well below the sustainable yields except in those areas where trading of animals and/or plants was introduced.

Man's agricultural use of land is a relatively recent event. The evolution of systematic agriculture of today is 200 years old and dates back to the days of the Industrial Revolution.

Agriculture has been considered as a way of life. Ever increasing population places greater demands on agriculture to increase the production, to match the increasing demands for food supply. With agricultural development though food production has successfully increased nearly everywhere but it has failed to match with the growing population in many areas - specially developing countries of Africa, Asia and Latin America.

This again has forced the pace of agricultural development to be maintained, so that teeming millions do not starve.

Over the period of time, the development of agriculture was achieved in terms of:

1. Expansion and /or conversion of agricultural lands;

2. Increased agricultural productivity;

3. Multiple-cropping pattern;

4. Conversion of single-cropping system to two tier and / or three tier cultivation and

5. Expansion of natural limits.

In due course of time, agricultural development became possible due to (a) development of modern scientific techniques; (b) advanced technology; (c) expansion of irrigational facilities: (d) use of chemical fertilizers; (e) use of pesticides and insecticides; (f) development and use of high yielding varieties of seeds; (g) changed agricultural practices; (h) mechanization of agriculture; (i) varying crop sequences and (j) land ownership and the land tenure.

It will be difficult for us to maintain our present standard of living and current consumption- pattern if we continue to destroy land. Considering this, it becomes essential to understand the related incidences causing environmental degradation.

(i) Expansion and Conversion of Agricultural Land

Increasing population growth at a fast rate, especially in the developing countries, has created enormous pressure on the virgin forest lands, cultural waste-lands and current fallow lands to be converted and brought under the cultivation or irrigation to ensure the food production substantially.

Conversion and expansion of agricultural land and forest areas changes in their natural limits. Thousands of millions of tons of soil is lost annually due to large-scale deforestation and/ or poor land management records chain reaction in the broad areas.

(ii) Application of Chemical Fertilizers, Pesticides and Insecticides

To assure enhanced productivity in areas where intensive cultivation has been initiated, increased application of chemical fertilizers supplying the plant nutrients has become an essential component of modern agriculture.

Fertilizer application in South Asia including India has multiplied with widespread introduction of the Green Revolution. Not only the number of fertilizer plants has gone up but also the production has multiplied, resulting in many a disorder.

(iii) The High Yielding Varieties Programme

The introduction of high yielding varieties has changed the agricultural environment by creating a variety of pest problems. Many of these either were unknown or were of minor importance in the early sixties.

The increased irrigational facilities, higher use of fertilizers and the high yielding varieties led to the resurgence of pests. The high-yielding varieties and the monoculture practices led to material change in the pest complex.

Pests and diseases such as gall midge, brown plant hopper, bacterial blight and tungro virus (or paddy) considered as minor diseases earlier to the Green Revolution suddenly appeared as major diseases.

Agricultural losses due to such pests and/or diseases increased tremendously since the high-yielding varieties were more prone to pests and diseases. Naturally, use of pesticides increased and this brought about widespread occurrence of pesticide-residues practically in every agricultural produce, widespread pesticide resistance in vectors and finally even resistance to pesticides in stored grains.

Such pesticide resistance in pests of agricultural importance became a major constraint in improving agricultural productivity.

(iv) Development of Irrigational Facilities

Irrigation has increasingly become indispensible. It has become a major consumer of water in many countries. Considering the nature of rainfall and scarcity of water and to meet the increasing needs of water in agriculture with the enhanced use of chemical fertilizers and pesticides, irrigational facilities have been developed to check the flow of surplus rainy water to avoid floods and also to regulate the avoidable water through canals to ensure the availability of water as and when required.

Heavy watering of agricultural fields by canals causes water logging and salinization a salt content move upwards due to capillary action and accumulates on the top layer of the soil. Accumulation of excessive salt contents in the soil converts the fertile soil/and into waste land due to salt layers at the top of the soil.

For example, "Canal-irrigated areas of Rajasthan", where due to heavy watering from the Indira canal system, vast areas have been adversely affected by salinization. Canal water also pours down huge amount of silt and sand which decreases the fertility of soils. Substance dissolved in irrigation water is especially liable to absorption and even trace concentrations of herbicides damaging crops.

The multiple cropping and intensive uses of chemical fertilizers and heavy watering of the agricultural land result in the rise of the water level. As a result, such areas have developed the problem of water logging, ultimately damaging the standing crops, microorganisms, animals and even the human population.

(v) Intensive and Extensive Cultivation

The introduction of intensive cultivation to get the maximum production and the variety of crops through multiple cropping, crop-rotations, changing crop-combination from the same unit of land has resulted in the decline of the productivity and total production due to critical limit of the soil.

Even use of chemical fertilizers also proves as ineffective. Wheat production in Punjab has declined due to the degradation of soil. In the process, land has been deteriorated due to loss of soil structure, loss of organic water, loss of plant nutrients and finally loss of soil itself.

(vi) Mechanisation

History of agriculture has been a succession of examples of the extension of cultivation with improved tools from the introduction of the first light plough to heavier and more effective and efficient ploughs with mechanised power.

The use of tractors, combined with harvesters increased with suitable machinery to work on difficult soils became practicable and has brought such lands under plough. Increasing use of machinery arid tractors with the development of two-tier and/or three-tier cultivation system has pulverized the land.

This has enhanced the possibilities of soil-erosion and easy movement of chemical contents to the lower horizons.