Intensive Agriculture and Environment
Globally, there are three systems of agriculture: traditional, intensive and industrial. Traditional agriculture is basically subsistence agriculture when a farmer lives in a small area of his farm or field and produces sufficient food for his family and have a small cash crop for the expenses. Intensive agriculture is an advanced form of agriculture where farmer puts efforts and money in form of more labor, irrigation, fertilizers, pesticides and machinery. This type of agriculture is common in the countries that depend too much on agriculture to feed their large populations and to sustain their economies. Industrial agriculture is growing the crops according to the specific market by identifying the demand beforehand.
Animal husbandry is an integral part of the intensive agriculture; resulting in the further requirement of land, food for animals, water and medicine. Besides this, intensive farming uses chemical fertilizers (mainly urea and diammonium phosphate), pesticides (mainly organophosphates and oregano sulfates) and machinery. Economically, intensive farming is beneficial to any country as it provides food for the people at affordable prices. It also saves the forest land because the same land is used for cropping over and over. But with the use of groundwater more and more, poor irrigation practices (like field flooding), planting of a crop in the wrong region (such as rice in dry and semi-dry areas), use of fertilizers and pesticides a number of environmental and even agricultural issues are arising; including soil salinity, water logging, water table depletion, nitrate poisoning, bioaccumulation and biomagnification of pesticides, loss of native crops etc. With the dawn of green revolution methods of irrigation, different types of pesticides, herbicides, insecticides, fertilizers (mainly urea and diammonium phosphate) and machinery were introduced to fields.
Irrigation practices included construction of canal systems which provided water for the fields in the far away areas and groundwater extraction (with tube wells and later on submersible pumps). The canal system caused the problem of waterlogging in some areas but the major impact was caused by exploitation of the groundwater by the tube wells and pumps. Overuse of groundwater caused an increase in soil salinity, the decline in the water table, water scarcity and degradation of water quality in the region of Punjab, Haryana and Western Uttar Pradesh, mainly. It’s been depicted as an overly exploited zone by geographical mapping system by NASA. Soil salinity leads to the degradation of the soil in such a way that soil becomes infertile. A major critical problem arising in North-West India is the cultivation of rice in the regions of low groundwater availability which is seriously affecting the water table. The cultivation of the crop should be according to the climate, soil type, and other resource availability. Methods like zero-tillage, sprinkler systems and drip irrigation should also be implemented according to the specific demand of crop and field conditions.
Pesticides’ overuse has caused dangerous problems of bioaccumulation (accumulation of the pesticides with a body over a period of time) and biomagnification (transfer of pesticides in the food chain, magnifying these to logarithmic scale). Being organic in nature, pesticides are fat soluble compounds and deposit in the fatty tissues in the body. It can lead from common toxicity to carcinogenic and teratogenic effects.
Chemical fertilizers have also caused accumulation of harmful ions such as nitrates and phosphates. Nitrates can reach up to groundwater table and can cause physiological problems such as blue baby syndrome in case of infants. Phosphates are known to be the most effective eutrophic agent when passes to water bodies such as lakes and ponds leading them to the stage of algal bloom. Farmers are not well-informed and educated about the amount of fertilizer use. Instead of overuse of fertilizers, farmers should explore the biotic and natural compost available in form of animal waste composting and crop residue composting.
Several methods used in intensive farming may be altered or new and old techniques may be used without any reduction in the production. These methods include biofertilizers such as dung-compost and vermicompost, crop rotation, planting crops according to the soil and water availability. Integrated pest management can be used in form of biopesticides such as Azadirachta oil, conservation of predator insects, manual weed eradication etc. Use of solar and biogas energy to reduce energy demand and use of organic waste for compost and fuel are also the tested methods.
Dr. Manbir Singh,
Department of Environmental Science,
Faculty of Allied Health Sciences