Transformation of applied phosphorus in neutral to alkaline alluvial and red soils

The variation in percent distribution of applied phosphorus in different P fractions was studied in different soils varying from sandy loam to clay, by adding superphosphate tagged with P32 to the soils. It was found that the P fraction was related to pH and texture of the soils. The order of distribution of applied P was Ca-P>Al-P>Fe-P>saloid-P in all soils except in the clay soil where the order was Fe-P>Ca-P>Al-P>Saloid-P. Percent P recovered as saloid-P and Al-P decreased with time while that of Fe-P and Ca-P increased. (author)