Maximum of applied P as superphosphate was transformed into inorganic P fractions as Al-P. R-P, Fe-P and Ca-P followed by diammonium phosphate and suphala + superphosphate at square formation, flowering and harvest stage of cotton. There was continuous increase in P fractions with increasing levels of P irrespective of growth stage. Ca-P was the most dominant P fraction in the soil followed by R-P at all the growth stages of the crop. Al-P, R-P and Ca-P were positively correlated with P uptake in cotton whereas, correlation between Fe-P and P uptake was not statistically significant with yield of cotton cv. NHH-44.
Phosphorus transformation, cotton, growth stage, P sources, Prates
