Dhr.ir. H.P. (Hendrik) Ritzema: “Subsurface drainage to combat waterlogging and salinity in irrigated agriculture in semi-arid and arid regions”

Salinity affects 10 to 16% of all irrigated lands while the annual rate of land loss due to waterlogging and salinity is about 0.5 million hectares per year. In this dissertation, the role of subsurface drainage to reduce these problems in irrigated agriculture in arid and semi-arid regions has been analysed and challenges for improving subsurface drainage practices have been formulated. Although the installed subsurface drainage systems are in general technically sound and cost-effective, drainage development lags behind irrigation development. This is mainly because the subsurface drainage systems are designed and implemented by government, with the users, the small farmers, having little responsibility and having little input. To reverse the negative trend in salt build-up and waterlogging in irrigated lands in semi-arid and arid regions, a number of challenges for enhancing the role of subsurface drainage have been formulated: (i) balancing top-down against bottom-up, (ii) from standardization to flexibility and (iiI) focus on capacity development.

Title thesis: 'Drain for gain: making water management worth its salt"