PEERJ, cilt.11, 2023 (SCI-Expanded)
Phosphorus (P) availability is the major constrain in obtaining optimum crop yield in calcareous soils due to its precipitation as dicalcium and octacalcium phosphate by reacting with Ca+2 and Mg+2. Therefore, we explored the role of phosphate solubilizing bacteria (without and with PSB @ 2 kg ha-1) in optimizing maize yield and P availability from soluble and insoluble P sources applied @ of 100 kg P2O5 into calcareous soil. PSB inoculation significantly improved maize plant height (5.6%), 1,000 grain weight (11%), dry matter (7.5%), stover (10.8%) and grain yield (6.8%), plant P concentration (10.1%) and uptake (18.6%), extractable P (3.1%), agronomic (48%) and uptake (53%) P use efficiency over uninoculated plots. Phosphorus application significantly improved maize yield, soil health and agronomic P use efficiency (4.84 times over control); however, its impact was more pronounced when applied as 50% P each from farmyard manure (FYM) and single super phosphate (SSP). On the basis of overall performance, the sources were ranked as 50% FYM + 50% SSP >50% rock phosphate (RP) + 50% SSP > 100% SSP > 75% FYM + 25% SSP > 75% RP +25% SSP > 100% FYM > 100 RP > control. Interactively, a significant and maximum increased over absolute control in most of the soil and plant tested characteristics were observed when 100 kg P2O5 ha-1 was supplemented 50% each as FYM and SSP along with PSB inoculation which was followed by 50% P each as FYM and SSP demonstrating that PSB were effective in enhancing RP solubilization under calcareous soil. Maximum value cost ratio of 3.1 was observed for 50% P each as FYM and SSP + PSB which was similar to 100% P as FYM + PSB and 75% FYM+ 25% SSP + PSB. Therefore, in calcareous soil P shall be amended 50% each as organic and mineral sources with PSB for its efficient utilization and obtaining optimum yield of maize.