Potassium Availability as Affected by Its Application to Rice at Two Moisture Regimes on Laterite Soils

Potassium application increased the yield of rice in greenhouse tests with two laterite soils one from West Bengal and the other from Karnataka, the latter having a higher content of available K than the former. The effect was more prominent when the soil was kept under continuous submergence or under alternate wetting and drying condition. Response to potassium in terms of both yield and uptake of K was relatively higher with the latter moisture treatment. The residual effect of the treatments (K and moisture) on wheat was reflected in increased uptake of K and also P in the soil from Karnataka.