High-intensity irrigated agriculture has fed the rising world population but degraded the land resource through water logging and secondary salinization. This book expresses fears about the permanency of irrigated agriculture. In this context, the history of irrigation and accompanying soil degradation in the Indian subcontinent is unparalleled.
The book begins with a brief discussion of the structural history, geology, physiography, climate and water resources of the subcontinent. It narrates development of irrigation from the primitive methods through the state-planned irrigation system of the Maurya period to the first large diversion of river water in south India by Chalukya kings some nineteen centuries ago.
The book examines groundwater-table rise in soils of major canal commands since the 1850s. Causes of water logging in India and Pakistan and remedial measures undertaken are presented in a historical perspective. Another chapter elucidates the connection between irrigation and soil salinity and explores prospects of problem-free irrigated agriculture.
The salt lands (and their native flora) in the subcontinent are also described, as are developments in classification and nomenclature and investigations on soil amelioration through surface and subsurface drainage, silting, tillage, manuring, and gypsum treatment. Real breakthroughs in understanding soil-salt-water relations came with knowledge about cation exchange and other advances in soils science. A detailed and critical appraisal of current research findings and their scope is presented.
Evolution of technology for the reclamation of salt lands, an evaluation of achievements in land reclamation, and prospects of saline irrigation are also discussed. The book concludes with a discussion of alternate uses of salt lands for forest plantations, pastures, and extraction of salts.
Nirmal T. Singh is a former director of the Central Soil Salinity Research Institute, Karnal, and the Central Agricultural Research Institute, Port Blair. He received a PhD in 1967 in soil science from the University of California, Davis. Dr. Singh holds fellowships from the Indian National Science Academy, the Indian Academy of Agricultural Sciences, and the Indian Society of Soil Science
