Soils of India

Soil is the thin, living layer on which almost all farming depends, formed by the weathering of rock, the action of climate, plants and animals, and the passage of time. India's soils vary with parent rock, rainfall and terrain, and the main types are well known to farmers and planners alike. Alluvial soil, found in the northern plains and river deltas, is fertile, deep and renewed by floods, and supports intensive farming. Black soil, also called regur, is found mainly on the Deccan basalt plateau; it is rich in clay, swells when wet and cracks when dry, and holds moisture well, making it suitable for cotton and other dryland crops.

Red soil, common across much of the peninsular plateau, gets its colour from iron oxides and is generally less fertile, needing fertiliser and irrigation for good yields. Laterite soil forms in areas of heavy rainfall and high temperature, as in parts of the Western Ghats, Odisha and the north-east, where leaching removes soluble minerals and leaves iron and aluminium oxides; it is poor for most crops unless improved, though it suits plantation crops such as cashew and tea in places. Arid and desert soils in Rajasthan are sandy, saline and low in organic matter, while mountain soils in the Himalayas are thin, stony and vary sharply with altitude and slope.

Soils face growing threats. Water and wind erosion strip topsoil from slopes and drylands; waterlogging and salinity damage irrigated soils, especially where drainage is poor; and continuous cropping without organic matter or balanced fertiliser use depletes nutrients. The Soil Health Card scheme, launched in 2015, gives farmers information on the nutrient status of their soil and recommendations for fertiliser use, aiming to reduce wasteful application and improve yields. Soil conservation measures include contour bunding, terracing on slopes, shelterbelts against wind, and maintaining organic matter through manure and crop rotation.

For civil studies, soil is a reminder that agricultural policy starts underground. Subsidies, irrigation, crop choice and land use all interact through soil: a fertiliser subsidy that ignores soil health, or an irrigation project without drainage, can damage the very resource it aims to help. Protecting soil is therefore cheaper than restoring it, and it connects farming to environment, nutrition and rural livelihoods in a single, practical chain.