SOLUBILITY ENHANCEMENT OF PHOSPHORUS FROM ROCK PHOSPHATE THROUGH COMPOSTING WITH POULTRY LITTER

Improving solubility of rock phosphate is critical for phosphorus (P) management in cropping. This experiment was conducted during 2010 to determine the P solubilized from rock phosphate (RP) through composting with fresh poultry litter (PL). The RP used in the experiment was collected from Hazara area of Khyber Pakhtunkhwa (KP) province, Pakistan. The treatments comprised of PL alone, PL+RP, and PL+RP+ Effective Microorganism (EM). Each treatment had 3 replicates. The compost was prepared in excavated pits of 3.13 m^3 size in anopen field for 120 days. The results showed that Mehlic-3 extractable P was significantly higher in the treatments PL+RP+EM, and PL+RP both at day45 and day120 of the incubation, compared to PL only. The increase in available P in treatment PL+RP+ EM was 55.2% and 928.6% over PL+RP and Control, on day120 compared to day0, respectively. Likewise, the increasing trend with time was higher in the treatments where RP was added to PL, irrespective of the treatments, compared to the control where no RP was added. The P availability enhancement in treatment PL+RP+EM with time could be due to the enhanced microbial activities of EM which have solubilize phosphate rock. Contrary to the available P, the nutrient content of nitrogen (N), Total Organic Carbon (TOC) and C:N decreased with the time in all the treatments. There was a significant decrease in pH values in the treatment of PL+RP+EM. The results of the study suggest that composting of PL with RP has the potential to enhance available P content of the compost or RPR.