Salinity and Iron toxicity

If water supply is not well managed, soil salinity may build up in paddy fields. Lack of surface drainage is found to be the main reason for salinity development in Sri Lankan paddy fields. Seepage and runoff water may collect in soil depressions or low-lying areas (due to purposeful blocking of drainage ways or by negligence of the farmers) and get evaporated, leaving dissolved salts in soil.. . Improvement of drainage will address the problem

Iron toxicity is largely found in the rice soils of up and low country Wet Zone and intermediate zone,   common in flat valleys and mainly confined places where interflow streamlines from adjacent landscape emerge within the valley. Interception of this interflow  by digging drains at the boundary between paddy land and adjacent highland can alleviate the problem. This can be achieved.