Desorption of soil phosphate by anion‐exchange resin

Kinetics of phosphate desorption from twenty soils by anion‐exchange resin were not satisfactorily explained by either film diffusion (or ion exchange mechanism) mechanism or particle diffusion mechanism. Eut the phosphate desorption process was adequately explained by a two‐constant rate equation. The two constants, the coefficient term (i.e., rate factor) and the constant term (i.e., solution P initially) were significantly correlated with amorphous Al; rate factor increased and solution P decreased with the increase in amorphous Al among the soils. Thus, influence of amorphous Al in P availability from soils must be considered.