Soil Salinity Dynamics in Raised Bed and Furrow (RBF) System and its Effect on Alleviating Waterlogging in the Coastal Lowlands

Abstract

In the coastal and humid tropical island regions waterlogging and soil salinity are serious threat to the sustainability of rainfed agriculture due to sea water inundation and intensive monsoonal rainfall. The present study was set out to evaluate and assess the raised beds technique to alleviate this problem in coastal lowlands. The raised bed and furrow (RBF) system reduced the overall salinity by 85%, improved the drainage of the raised beds, harvested rain water, and prevented entry of tidal and runoff water into the furrow. Based on the rate of reduction in salinity lag phase, leaching phase and equilibrium phase were recognised during the leaching of salts from the raised beds. But coastal lowlands experienced waterlogging (5-81 cm) and salinity (3.0-9.1 dS m-1) which closely followed the rainfall pattern. Waterlogging and salinity peaks at different seasons requiring different management strategies but, raised bed and furrow system are effective in addressing this challenge together.