Abstract
n a field study, gypsum, in addition to HCI and H~SO~, equivalent to 100% gypsum requirement, was used to reclaim a dense saline sodic clay loam soil during rice cultivation. Soil samples collected at two depths after the rice crop were analysed for total K+ and mineralogy. Mica wasthe major K+ mineral in the soil. Total K+, mica and srnectite decreased more profoundly in acid treated soil than 'in the gypsum and untreated soils. It is suggested that the proton (H t) from acids extracted interlayer K+ from mica and converted it to vermiculite which fixed applied K ". This could explain the reason of K deficiency in wheat sown 'after rice in acid reclaimed saline sodic soils.
