Integration of poultry manure and phosphate solubilizing bacteria improved availability of Ca bound P in calcareous soils

A laboratory incubation experiment was executed to examine the role of phosphate solubilizing bacteria (with PSB and without PSB) and poultry manure (4, 8 and 12 t PM ha(-1)) in improving P mobilization/mineralization under four different lime regimes (4.78, 10, 15 and 20% CaCO3 M/M) for 56 days using three factorial complete randomized design (CRD) with triplicates. Phosphorus availability progressively increased over time irrespective of PSB inoculation, PM and lime levels. The PSB and PM (4-12 t ha(-1)) addition into soil significantly increased Olsen P at all incubation intervals. Post incubation PSB survival increased by 12 and 9% with inoculation and 12 t PM ha(-1) over control and 4 t PM ha(-1), respectively. Liming ominously reduced P mobilization/mineralization by 1.3, 2.6 and 10.5% and PSB population by 6.6, 7.3 and 16.3% at 10, 15 and 20% (lime), respectively, over control at day 56. However, PSB and PM addition (with increasing rate) into soil significantly counterbalanced these ill effects of lime. Thus, the application of PSB and PM is a promising measure to enhance P availability in calcareous soils and shall be practiced.