Sustainable Agriculture for Competitive exam : Agrilearner

• Sustainable agriculture is a form of agriculture aimed at meeting the needs of the present generation without endangering the resource base of the future generations.

• Sustainable agriculture is minimal dependence on synthetic fertilizers, pesticides and antibiotics.

• It is also considered as a system of cultivation with the use of manures, crop rotation and minimal tillage.

• Sustainable agriculture system has to be economically viable both in the short and long term perspectives.

• Sustainable agriculture is also known as eco farming or organic farming or natural farming or permaculture.

• Sustainable agriculture is known as eco farming as ecological balance is given importance.

• It is called organic farming as organic matter is the main source for nutrient management.

• Organic farming is agricultural production system which avoids or largely excludes the use of synthetically compounded fertilizers, pesticides, growth regulators and livestock feed additives.

• To the maximum extent feasible organic farming systems rely upon crop rotations, crop residues, animal manures, legumes, green manures, mineral bearing rocks and aspects of biological pest control to maintain soil productivity and tilth to supply plant nutrients and to control insects, weeds and other pests.

Pest management practices in organic agriculture:

Crop rotation
Strip cropping to moderate spreading of pests over large areas
Manipulation of planting dates, planting crop at optimal time
Adjustment of seed rate, high seed rate reduces weedsor insects.
Use of appropriate plant varieties
Biological control methods
Pheromone traps
Biological pesticides (pyrethrum)

• Characteristics of sustainable agriculture

1) FYM, compost, green manures, biofertilizers and crop rotations are used for nutrient supply

2) For pest control cultural methods, crop rotation and biological methods are used

3) High diversity, renewable and biodegradable inputs are used

4) Stable ecology

5) Rate of extraction of resources do not exceed rate of regeneration

6) Food materials are safe

• Ozone concentration of the atmosphere is declining at nearly 0.5% per year due to release of chlorofluorocarbons, nitrogen oxide and methane.

• For every one molecule of chlorine released from chlorofluorocarbon, about 1 lakh molecules of ozone are removed from ozone layer.

• Carbon dioxide and water vapour are transparent to visible solar radiation and so allow light to pass through, but they prevent infrared radiation from escaping and thus effectively trap solar heat.

• Atmospheric carbon dioxide by trapping solar heat produces greenhouse effect and heats up the atmosphere.

• It is estimated that earth’s mean temperature would have been as low as -23oC without CO2 rather than +15oC as it is today.

• Now CO2 concentration in atmosphere is around 402 ppm.

• Out of the total geographical area of 329 mha in India, 265 mha is suitable for crop production and about 175 mha is affected by soil related constraints and are classified as wastelands.

• Soil erosion by water in the form of rill and sheet erosion is a serious problem in the red and lateritic soils of south and eastern India where about 40 t/ha of top soil is lost annually.

• Out of 70 m ha of black soils of central India, 6.7 m ha are already unproductive due to the development of gullies, ravines and torrents.

• Shifting cultivation practiced largely in the north-eastern India has caused serious land degradation over 4.4 m ha of land.

• Deforestation is estimated to be proceeding at the rate of about 1.5 m ha per year.

• Earlier forest cover of Himalayas was 60% and it is now estimated to be only 25%.

• Due to improper management of irrigation water, salinization and alkalization of soil takes place.

• An area of 6 m ha of land is affected by waterlogging.

• 7 mha land is salinised due to faulty irrigation practices.

• Disadvantages of sustainable agriculture are

1) Low yields

2) Lack of timely and effective control of weeds, insects and diseases

• Conversion from modern agriculture to sustainable agriculture usually takes 3-6 years.

• Sustainable agriculture movement started in 1981.

• The use of limited quantities of fertilizers and discrete application of small quantities of target specific pesticides at critical stages of crop damage will be in agreement with the principle of sustainable agriculture.

• Indices of sustainability may be simple involving one parameter or complex involving several parameters.

• Indices of sustainability were given by Lal (1994).