Biochemical Transformation of Fertilizer Phosphorus when Mixed with Organic Matter

Rock phosphate (MRP) from Mussoorie (U.P.) and triple superphosphate (TSP) were added to fresh cattle dung @ 0.5, 1.0 and 2.0 per cent P on dry weight basis and were incubated (30 ± 4°C) at 80% moisture saturation for 105 days. Higher recoveries of organic P were obtained with TSP as compared with MRP at the initial stages, but subsequently a reverse trend was observed. In the control samples inositol-P, lipid-P, fulvic acid and humic acid associated-P increased up to 31, 74, 58 and 105 days, whereas with phosphate treatment these forms increased up to 41–60, 91–105, 59–60 and 83–105 days, respectively. Thereafter a decreasing trend was obtained. All these forms increased with higher levels of P. Immobilization of P was more in TSP treated samples largely in the form of lipid-P and humic acid-P, while a reverse trend was noted in the case of MRP treatment.