Managing Land and Water Resources in Sundarbans India for Enhancing Agricultural Productivity

Abstract

Agriculture in Sundarbans is plagued with adverse land and water conditions. The answer to the problem of improving agricultural production and productivity in this region primarily lies with the tackling of problem of surface drainage in the monsoon season and through water availability during post-monsoon season. The various strategies suggested in this chapter from the points of view of improved land and water management under the existing situations in India narrated above include (i) rainwater management through storage in on-farm reservoir, derelict channels, other canals, etc., (ii) channelization of the catchment and regulated operation of the sluice gates, (iii) land management through levelling, bunding, raising of crop beds, and (iii) improved crop planning against constraints due to drainage congestion during monsoon as well as to limited irrigation water availability during dry periods. Simulation studies using a soil water balance model for rainfed lowland rice is used for estimating excess rainwater to design on-farm reservoir (OFR) and to assess surface drainage improvement due to storage in OFR. Weekly rainfall at 2 and 5 year-return periods are used to optimize the size of OFR and to simulate surface drainage improvement, respectively. It is recommended to convert 20% of the farm area into OFR to harvest excess rainwater, and also to reduce surface waterlogging to the extent of 75%. Further, a simple linear programming model is used to propose optimal land allocation for rabi (winter) crop cultivation to increase the agricultural profit under various limitations of land and water.