OPTIMIZING SUBSURFACE DRAINAGE PRACTICES IN IRRIGATED AGRICULTURE IN THE SEMI-ARID AND ARID REGIONS: EXPERIENCES FROM EGYPT, INDIA AND PAKISTAN

In this paper, the role of subsurface drainage in irrigated agriculture in semi-arid and arid regions is discussed based on experiences obtained in Egypt, India and Pakistan. Agriculture in these countries is predominantly practiced by small, marginal farmers with landholdings of often less than one hectare. In general, they do not have the means to pay for the investments in irrigation and drainage themselves. Consequently, most irrigation and drainage projects are funded by the ( local) governments. Shallow horizontal pipe drainage systems have proved to be a technically feasible and cost-effective tool to combat the twin problem of waterlogging and salinity. Their large scale implementation is, however, hampered by a number of institutional and socio-economic reasons. The paper discusses why subsurface drainage is needed to safeguard investments in irrigated agriculture and to conserve land resources, as well as what the challenges are to make subsurface drainage work. Copyright (C) 2010 John Wiley & Sons, Ltd.