Subsurface drainage to increase rice productivity in a saline environment

Abstract

The average productivity of rice in India-at less than 2 t ha-l-is, by all standards, low (MIB 2003). Irrigated rice yields in the range of 2.5-4.0 t ha-l in many places are far from their anticipated productivity of 6.0-7.5 t ha-l. Such low yields, in many cases, can be due to salt-related soil degradation. As such, a rising water table, appearance of salt efflorescence at the soil surface, and declining rice yields cause farmers, researchers, and policymakers to worry because those problems can jeopardize the future of irrigated agriculture and bring about downtrends in the economy. Based on the outcome of baseline and soil surveys, it has been hypo- the sized that large areas going out of cultivation and low yields can be attributed to the high water table, accompanied by salt-related land degradation. Studies began under an Indo-Dutch Network Project at 10 locations in four irrigation commands covering two states of India to assess the yield-salinity relationships for rice and to test improved drainage techniques to reverse or mitigate salt-related problems.