In vitro solubility of P from the different type rock phosphate along with PSBs and organic substrates

P is an important primary nutrient for the crop growth as root development, seed quality and energy currency. P use efficiency generally ranges within 15-20%. Commercially available P fertilizers immobilized in soil owing to formation of insoluble mineral complexes with Ca2+ (Tricalcium phosphate), Fe3+ (Strengite) and Al3+ (Variscite) making it unavailable to plants after application. Organic form of P constitutes 20–80% of total soil P and remaining form is in inorganic form (apatite, strengite and varicite). Burkholdaria cariabensis, PSB1: B. cepacia, PSB2; Rock Phosphate (Udaipur): RP1, Rock Phosphate (Purulia): RP2; FYM (dosage) 200 Q/ha and Vermi-Compost (VC):5 t/ha. were applied to the soils. Lowest pH (6.44) was observed at 60 days after incubation in alluvial soil whereas the encountered lowest pH value (4.29) at 60 days incubation period in red soil. Higher pH was dropped in PSB1 treated soil as compared to PSB2 whereas FYM and PSB1 treated soil more decreased in pH over the VC and PSB2. Phosphorus solubilization was resulted lower in case of red soil as compare to alluvial soil, in other hand phosphorus solubilization was increased with lapse of time interval. Udaipur rock phosphate was recorded higher solubilization of phosphorus over the purulia rock phosphate. Coinoculation of PSBs along with RP1 or RP2 was resulted lower in phosphorus solubilization as compared to Coinoculation of PSBs with FYM or VC.