This is particularly acute in India, which has only 2.4 per cent of the world’s geographical area but supports over 16 per cent of the world’s population. It has 0.5 per cent of the world’s grazing area but has over 18 per cent of world’s cattle population. These pressures have led to drastic changes in the proportion of land utilised for agricultural activities, urbanisation and industrial development.
The main causes of land degradation are as follows:
1. Salinity and Water logging due to Intensive Farming:
Intensive agricultural practices that rely heavily on water, chemical fertilisers and pesticides have caused waterlogging and salinity in many parts of the country. The expansion of the irrigation system without adequate steps for treatment of the catchment areas has exacerbated this. The quest for increased agricultural productivity has led to intensive cultivation of marginal lands causing their degradation.
These pressures on land are compounded by the fact that over 69 per cent of our geographical area falls within dry zone as per the Thornwaite classification. Land degradation has a direct bearing on the productivity of soil, its vulnerability to rainfall variations, scarcity of drinking water, fodder and fuel wood. Given the interlinkages of crop production, livestock economy and environment, land degradation has a major impact on the livelihoods of the people, especially in rural areas.
2. Soil Erosion:
Soil erosion is a serious problem in hills, and arid semi-arid areas. Some plains have also been affected by soil erosion. Besides natural causes, there are some human activities also, which cause degradation of land. These are degradation of natural vegetation caused by overgrazing by animals, deforestation and careless management of forests.
3. Mining and Industry:
Mining and Industry are two important activities of human kind. Surface mining leads to degradation of land. The mining sites are abandoned after excavation work is complete. The mineral processing, like grinding of limestone for cement industry, and calcite and soapstone for ceramic industry, generates heavy amount of dust and releases it in the atmosphere.
It later on settles down in the surrounding areas, affecting infiltration of water and crop cultivation. In recent years, industrial effluents and wastes have become a major source of land and water pollution in several parts of the country.
Extent of Land Degradation:
Wasteland differ considerably due to definitional and coverage inconsistencies. According to the land use statistics for 2002 published by Department of Agriculture, the current estimates of culturable wasteland are 13.9 million hecatres (m ha). However, the information on the land use statistics does not clearly indicate the extent of wasteland and degraded land, which could be restored with some interventions.
National Remote Sensing Agency (NRSA) carried out a district-wise mapping of wastelands on 1:50,000 scale using satellite data. The wastelands in the country were placed at 63.85 mh. They occur in different agro climatic and soil zones of the country. These wastelands form the core of degraded lands in India. They are in urgent need of attention and have to be accorded the highest priority for treatment under watershed programmes.
Some of the most degraded lands in the country are the common property resources (CPRs). CPRs are resources on which people have an equal right of use. These resources include community pastures, community forests, wastelands and common dumping and threshing grounds.
Inspite of concerted efforts to check deforestation and the various afforestation schemes taken up during successive Plan periods, large tracks of forest continue to be classified as degraded.
The 1999 Forest Survey of India placed the actual forest cover at only 19.39 per cent of the total geographical area as against the recorded forest area of 23 per cent. Of the total forest area, 31 m ha suffers from some form of degradation and 14.06 m ha of forests suffer from extreme degradation and are part of 63.85 m ha of wastelands reported by the NRSA.
In addition to the wastelands identified by the NRGA, other areas such as deserts, drought-prone, flood-prone and tribal areas have been subjected to severe forms of degradation. The capacity of these lands is limited due to environ-mental factors. Pressures of human and livestock population have further compromised them.
These areas co-relate very strongly with the incidence of poverty in the country. The prevention of land degradation and the augmentation of the carrying capacity of land to provide food, fuel and fodder requirements have, therefore, been a primary concern of the Government. Special Area Development Programmes have been funded to mitigate the harsh living conditions of people through better land management, water harvesting and conservation practices on a watershed basis.