Effect of submergence on the availability of toxic and deficient nutrients in acid sulphate soils of Kerala

Abstract

Laboratory incubation experiments were conducted with acid sulphate soils of Kerala to investigate the changes in pH exchangeable iron, manganese, aluminium, calcium and potassium. It was noted that flooding resulted in an increase in the soil pH and the extent of increase was determined by certain inherent characters of the soil. The exchangeable Fe content increased and reached a peak value in 30 days and then decreased. The amount of Fe released was dependent on the active iron content of the soils, of submergence. As for Mn Ac/;' and Kayal soils showed a higher release of Mn on flooding. But all the other soils showed only very little change. The course of change of exchangeable Mn was similar to that of Fe. The overall effect of submergence was towards an increased availability of Ca and K.