Soil Erosion in India affects farming in detrimental ways. Agriculture being the prime occupation of the nation gets harshly affected due to soil erosion. Physical damage is the most visible form of soil loss and most likely to be remedied.
Soil Erosion occurs when gravity pulls the soil constantly, nudging it down hill, causing soil slips, earth clips, cracks, creep and slumps. Ironically, the most damaging of all is the rainfall, when the water droplets hit the soil. From there on, the flow of water causes sheet-wash, rilling, surface gullying, tunneling and in rivers it scours banks. In dry climates, wind blowing is the main cause of soil erosion. Soil Conservation is a set of methods and procedures, which are adopted for prevention of soil being eroded from the earth`s surface or becoming chemically changed by excessive use or salinization or acidification. The main methodology of soil conservation are improvement of the choice of vegetative cover, soil erosion prevention, salinity management, to expand the health of beneficial soil organisms and checking of soil contamination. Soil conservation is of utmost importance for a country like India, which is mainly possesses an agricultural economy.
Soil is the non-renewable natural resource, which supports life on earth and in a survey it was estimated that one-sixth of the world`s soils have already been degraded by water and wind erosion. This has two important consequences; firstly, the reduced ability of society to produce sufficient food due to loss of quality and depth of soils; and secondly the off-site pollution effects connected with erosion. These include siltation of dams, pollution of watercourses by strong agricultural chemicals and damage to property by soil-laden runoff. On-site issues of declining soil quality tend to be spatially dispersed occurring on many different soil types whereas off-site pollution issues tend to be locally concentrated.
In India almost 130 million hectare of land (45% of total geographical surface area) is affected by serious soil erosion through gorge and gully, shifting cultivation, cultivated wastelands, sandy areas, deserts and water logging. Soil erosion by rain and river that takes place in hilly areas causes severe landslides and floods, while cutting trees for agricultural implements, firewood and timber; grazing by a large number of livestock over and above the carrying capacity of grass lands, traditional agricultural practices, construction of roads, indiscriminate quarrying and other activities, have all led to the opening of hill-faces to excessive soil erosion.
Wind erosion cause development of deserts, dust, storms, whirlwinds and destruction of crops, while moving sand covers the land and makes it sterilized. Excessive soil erosion with resultant high rate of sedimentation in the reservoirs and decreased fertility has become solemn environmental problems with catastrophic economic consequences. Soil erosion results in huge loss of nutrients in suspension or solution, which are washed away from one place to another, thus causing depletion or enrichment of nutrients. Besides the loss of nutrients from the topsoil there is also degradation through the creation of gullies and ravines, which makes the land unsuitable for agricultural production. Subsidence of the land in some areas and landslides in the hilly regions are problems that affect highways, habitations and irrigation dams.
The use of pesticides at excessive rates enters the food chain, causing health hazards. A major concern particularly about chlorinated hydrocarbons like DDT is their everlasting persistence in soil. Among fertilizers the conversion of fertilizer-N to gaseous forms-ammonia (NH3) and various oxides of Nitrogen leads to atmospheric pollution. Escape of fertilizer-N as ammonia gas is called ammonia volatilization. The presence of ammonia and sulphur dioxide may lead to acid rains, which ultimately degrade the soil. Atmospheric ammonia contaminates water bodies, weakens visibility and causes corrosion. Nitrous oxide also contributes to global warming. The activity of mining and quarrying covers underground and surface mines, quarries and wells and includes extraction of minerals and also all the supplemental activities such as covering and benefaction of ores, crushing, screening, cleaning, washing, grading, milling floatation, melting floatation and other preparations carried out at the mine site which are needed to render the material marketable. These activities also enhance the occurrence of soil erosion.
The Indian government is trying out various procedures of soil conservation to check upon the damages caused by this phenomenon. However, soil erosion through natural agencies can hardly be checked, but the artificial means like mining, deforestation and others are being strictly brought under the umbrella of law.
