Modification of phosphate-ion transfer in a cropped Colombian oxisol with P fertilization

The transfer of P ions between soil and solution is a factor that often limits plant production in Oxisols in native savannahs of Colombia. Changes in this transfer due to P fertilization and cropping were examined by isotope dilution. For a given P addition, cropping and fertilization significantly decreased the affinity of the soil's solid phase to react with P ions in solution, giving a higher concentration of P ions in solution and replenishment of P in cropped soils. The ability of the soil solid phase to react with phosphate (P) ions in solution is of prime importance to characterizing soil P availability and P fertilizer efficiency, especially in P-deficient Oxisols. Changes in P-ion transfer between the liquid and soil solid phases were analyzed in a cropped and P-fertilized Colombian Oxisol by isotope dilution