Experiences from Subsurface Drainage Technology Pilot Areas of Andhra Pradesh, India

The rapid development of canal irrigated areas and consequent supply of irrigation water at a highly subsidized price has disturbed hydrological equilibrium and caused adverse effects on soil and ground water quality in many canal command areas in India. There has been a rise in the water table and consequent degradation of soils through waterlogging and secondary salt build up in these command areas. This has caused millions of hectares of land gradually going out of production or experiencing reduced yields. It is estimated that an area of 8.4 million ha is affected by soil salinity and alkalinity in India. Large areas of prime agricultural land in some of the irrigation commands in Andhra Pradesh state of India are constantly waterlogged, while other commands are affected only during the post-monsoon season. The waterlogged and salt affected areas in Andhra Pradesh are estimated at around 0.46 million ha. Eight subsurface drainage pilot areas have been established in Andhra Pradesh as a part of various research projects over the past 25 years and the performance of these drainage systems has been evaluated. This paper reviews the experiences from these drainage pilot areas in Andhra Pradesh.