Agriculture refers to the practice of rearing domestic animals and crops with the goal of
food production. Although agriculture is essential in sustaining human life, the practices
associated with it have been known to have certain impacts on the environment. The
most notable of these effects includes climate change, deforestation, pollution, and
general environmental degradation.
Environmental Impacts Of Agriculture
Climate Change
Agriculture and climate change have a reciprocal relationship. Climate change affects
agricultural production through precipitation levels and temperature variations. In return,
poor agricultural practices increase climate change. The most significant climate change
associated with agriculture is brought about by methane, nitrous oxide and carbon
dioxide, all of which are greenhouse gases released into the Earth’s atmosphere from
farming. Pesticides and fertilizers application affect the quality of air through production
of compounds like phosphorus, nitrate and ammonia.
Pollution
In order to enhance agricultural production quantity and quality, several additives to the
soil are used in farming. The widely used are pesticides and fertilizers, which end up as
pollutants in water run-off from the soil. This run-off can adversely affect more people
and animal wildlife.
Soil Degradation
In all ecosystems, the biodiversity held in soil is massive. Healthy soils are vital to
creating ample food production. Although agriculture is not the sole cause of soil
degradation, poor farming practices are known to cause a considerable decline in in the
quality of soil. This mainly results from pesticide contamination, waterlogging and
salting. Soil erosion leads to loss of soil fertility and structure.
Deforestation
Across the globe, cases of forests being cleared for agricultural reasons is on the rise
with people seeking to increase their scales of agricultural production. Deforestation
provides more land for crops and pasture. Deforestation enhances the effects of climate
change. Destruction of habitat amongst species also leads to fragmentation and
depletion. Extensive deforestation affects the water cycle, which results in interferences
with precipitation.
How Can the Environmental Impacts Of Agriculture Be
Mimimized?
The key to protecting the environment against the harmful effects of extensive and
unsafe agricultural practices is through sustainable practices. Sustainable farming
incorporates both the conservation of available resources as well as employing farming
practices aimed at environmental protection.
The following points highlight the five main impacts of
agriculture on environment. The impacts are:- 1.
Degradation of Land 2. Deforestation 3. Biodiversity 4. Pest
Problem 5. Disposal of Industrial & Agricultural Wastes.
Impact # 1. Degradation of Land:
The degradation of land in one form or the other is matter of serious
concern endangering sustainability of agriculture. Landslides caused
by rains and flowing water in hilly areas and deforestation,
overgrazing and faulty cultural practices in the forest and other plain
areas expose the soil to water and wind erosions. As may be seen from
Table. 1, out of total geographical area, 141.3 million hectare (10.3 per
cent) area is subject to such water and wind erosions.
The waterlogging due to rising water table, particularly along the
rivers, rendering soil unfit for cultivation, covers 8.5 million hectare
land. Similarly, increased dependence on intensive agriculture and
irrigation also resulted in salination, alkalination and water logging in
the some irrigated area of the country.
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Therefore apart from problem soils forming a significant
part of the total area, the following are the kinds of land
degradations taking place:
(a) Deficiency of soil nutrients due to intensive cultivation.
(b) Imbalance in soil nutrients particularly the deficiency of micronutrients.
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(c) Decline in the organic matter in the soil.
(d) Deforestation and overgrazing of Pasteur’s causing exposure of soil
to water and wind erosion.
(e) Decline in underground water due to over exhaustion for high
water using crops, increase in cropping intensity and increase in
cultivated area especially is northern part of the sweet water zone.
(f) Increase in water level in the cotton belt of north-western part of
the country endangering then cultivation of cotton crop due to
pumping out of brackish water resulting in accumulation of salts on
earth surface. Further, the wet condition due to non-percolation of
rain water attracts serious pests.
(g) High use of nitrogen and water have caused percolation of nitrogen
up to water table thus polluting it even for human consumption.
Impact # 2. Deforestation:
The forest cover estimates are given in Table 2.
The main reasons for decline in forest wealth are:
1. Increase in population resulting in more demand for fuel wood and
timber.
3. Indiscriminate siting of development projects.
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4. Forest fires.
5. The forest area in the recent past has not changed much because its
diversion for non-forestry purposes has been more or less
compensated by afforestation.
“The annual withdrawal of fuel wood is estimated at 235
million cubic meters against a sustainable capacity of about
48 million cubic meters. The annual demand for industrial
wood is 28 million cubic meters against the production
capacity of 12 million cube meters. The area affected by
forest fire ranges from 33 percent in West Bengal to 99
percent in Manipur.”
Impact # 3. Biodiversity:
India is a country with wide variety of agro-climatic conditions which
harbour a wide variety of animals and plants. According to an
estimate, India ranks 10th in the World and 4th in Asia in terms of
plant diversity. As agriculture is becoming more and more
commercialized, a number of plant and animal species are becoming
extinct.
The crops showing high profits are covering more area while the less
profitable ones are rapidly declining, creating a number of
environmental problems. The depletion of vegetative cover such as
grass lands and forest tree species and similarly extinction of wild
animals, birds and insects is matter of concern. According to another
estimate, over 1,500 plant species, 79 mammals, 44 birds, 15 reptiles,
3 amphibians and several insects are listed as endangered.
Impact # 4. Pest Problem:
With the shift in crop pattern, increase in area under irrigation and
higher cropping intensity, the pest problem has become very severe.
The seriousness of pests has further increased by way of
indiscriminate and increased use of pesticides.
The predatory birds and insect population has dwindled at a sharp
rate causing lack of natural control of pests. The direct effect of high
use of dangerous pesticides is on human and animal health. A large
variety of cases of residual effect of pesticides and intake by human
and animals have created health hazards.
It is clear from table 3 that the use of pesticides increased at a fast rate
in the country. It was 24.3 thousand tonnes of Technical Grade
Material in 1970- 71 which increased to 75.0 thousand tonnes in 199091, thereafter it started falling, touching a level of 56.1 thousand
tonnes in 1996-97 and 38 thousand tonnes in 2006-07. The recent
decline in the pesticide use is due to increasing awareness among
producers and consumers about the ill-effects of pesticides.
Impact # 5. Disposal of Industrial & Agricultural Wastes:
The use of by-products such as paddy straw and rice husk has not been
made properly. The burning of such by-products creates increase in
carbon dioxide and carbon-monoxide in the atmosphere resulting in
respiratory problems for animals and human beings. There is need for
recycling the agricultural wastes by having enterprises like dairy,
poultry, fishery etc., processing of by-products and ploughing in the
field as organic matter.
The mechanisation of agriculture require various energy resources
such as diesel, electricity, petrol etc. Moreover, higher use of fertilizers
as well, has negative impact on the ecology of the country by air
pollution. Affluent water, smoke and un-degradable solid waste from
industries and domestic uses have also been responsible for toxicity in
plant and animal particularly fish and unbalanced soil nutrients which
needs to be checked through treatment plants.