Land Degradation in India
-Dr. Arvind Singh
Land is an important natural resource, which provides food, fuel, fodder, and timber to us. Unfortunately, the land has been exploited and abused mercilessly from centuries resulting in the enhanced rate of land degradation. Land degradation means loss in the capacity of a given land to support the growth of useful plants on a sustained basis. Land degradation is a big loss to the economy as the land loses its production potential and gets converted into wastelands. Hence shrinking of the land resource base is a big problem before developing country like India. The per capita man-land ratio in India is hardly about 0.48 hectares, which is lowest in the world.
Types of land degradation:
Land degradation is categorized into three types i.e. (i) Physical degradation (ii) Biological degradation (iii) Chemical degradation. Physical degradation refers to a deterioration in physical properties of soil whereas biological degradation refers to reduction in soil organic matter, decline in biomass carbon and decrease in activity and diversity of soil fauna. Chemical degradation is basically due to nutrient depletion.
Extent of land degradation:
Degraded land includes eroded lands, saline / alkaline lands, water logged lands and mined lands. The total land area of India is 329 million hectares of which about 178 million hectares (54%) is converted into wastelands for one or other reasons. This also includes about 40 million hectares of degraded forest. The total cultivable land of the country is about 144 million hectares of which 56% (80.6 million hectares) is degraded due to faulty agricultural practices and the dense forest cover has been reduced to 11% (36.2 million hectares) of the total geographical area. Watershed areas, river corridors, and rangelands have been extensively disturbed. The situation is frequently so bad that even cessation of abuse may no longer lead to self-restoration of biological diversity, stability, and productivity of the ecosystems.
In India, about 25% of the land area is suffering from the problem of water erosion. 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 tonnes per hectares of top soil is lost annually. Out of 70 million hectares of the black soils of Central India about 6.7 million hectares are already unproductive due to the development of gullies. Over 4.4 million hectares of land is degraded due to shifting cultivation practiced largely by tribals in North-eastern India.
Ravines are a system of gullies or gorges worn out by torrents of water running more or less parallel to each other and draining into a major river or its tributaries after a short distance with development or deep and wide gorges. In fact, ravine lands are a manifestation of an extreme form of water erosion occupying approximately 3.67 million hectares of land chiefly distributed in Uttar Pradesh, Madhya Pradesh, Rajasthan, and Gujarat. It has been estimated that the production potential of ravine areas in Uttar Pradesh, Madhya Pradesh and Rajasthan alone would amount to 3 million tonnes of food grains annually besides fruit, fodder, and wood. On a conservative estimate, the country is losing a total output worth about Rs.157 crores a year by failure to reclaim and develop the ravine lands. Furthermore, these ravine lands have been creating the problem of law and order maintenance in states of Uttar Pradesh and Madhya Pradesh as the notorious dacoits take refuge in these eroded lands and conduct their unlawful activities.
Wind erosion in chiefly the problem of arid and semi-arid regions of the country where the soil is sandy with scanty vegetation or even without vegetative cover. In India about 50 million hectares of land area is affected by wind erosion most of which belong to Rajasthan and Gujarat. Over-grazing is the main cause of soil erosion in these areas. It is estimated that a program for the control of wind erosion covering 50 million hectares would cost about 3,000 crores of rupees.
Approximately 140 million hectares of land area of the country is affected from water and soil erosion as a result of which the top fertile layer of the soil is lost annually at the rate of 6,000 million tonnes per year containing more than Rs.1,000 crores worth of nutrients. The number of macronutrients like nitrogen, phosphorus, and potassium (N, P & K) lost during this process is about 5.53 million tonnes.
Causes of land degradation:
Population explosion, intensive cultivation, industrialization, urbanization, deforestation, over-grazing, shifting cultivation, mining activities are the chief causes of land degradation in India. Besides these, modern agricultural practices are also the cause of land degradation. The advent of the Green revolution in mid-sixties has led to increased use of chemical fertilizers and pesticides which has not only polluted the atmosphere but also has caused a significant decline in the floral and faunal population of the soil, which is responsible for the maintenance of soil fertility. This has resulted in a decline in land productivity.
Overuse of nitrogenous fertilizer urea has caused the acidification of the soil. In acidic soil elements like phosphorus, copper and zinc are unavailable to the plants. At the same time, acidic soils are generally poor in micronutrients like calcium and potassium. Thus the ultimate result is a loss in production potential of the land.
Indiscriminate use of inorganic fertilizers destroys the soil structure in which the soil particles are aggregated together into crumb consequently the soil becomes prone to erosive forces like water and wind.
Excessive use of water for irrigation practices has caused the soil salinity/alkalinity as a result of which fertile lands have been converted to usarlands (salt-affected soils). About 6 million hectares of the land area are affected by waterlogging and about 7 million hectares is salinized/alkalinized due to faulty irrigation practices. Approximately 40% of the salt-affected soils occur in Indo-Gangetic Plain extending over Hariyana, Punjab, Uttar Pradesh, Bihar, and Delhi. In saline/alkaline soils the high concentration of salts, lack of moisture availability, poor permeability, the toxic effect of sodium ions, high alkalinity and nutrient disorders are important factors inhibiting plant growth.
Conclusion:
It can be concluded that land degradation is a serious problem in India which need to be tackled because shrinking of land resource base will lead to a substantial decline in food grain production which in turn would hamper the economic growth rate and there would also be an unprecedented increase in mortality rate owing to hunger and malnutrition.
-X-X-X-X-X-
Dr. Arvind Singh is M. Sc. and Ph.D. in Botany with an area of specialization in Ecology. He is an active Researcher having four dozen published Research Papers in the journals of national and international fame. keywords: soil degradation in india, soil degradation definition, soil degradation causes, soil degradation effects, soil degradation meaning, soil degradation conclusion, soil degradation and remedial measures, land degradation causes, land degradation in india, land degradation definition, land degradation in irrigated areas, land degradation solutions, land degradation effects, What is degradation of resources?, What are the causes of land degradation?, What are the effects of land degradation?, What is land desertification?