Integrated use of phosphorus sources, phosphate solubilizing bacteria, and rhizobium enhanced growth, nitrogen, and phosphorus uptake in chickpea

Expensive phosphatic fertilizers and limited phosphorus (P) availability hamper chickpea production in calcareous soils. Using cheaper P sources could reduce production costs. A field experiment assessed the combined effect of single superphosphate (SSP) and rock phosphate (RP) ratios (RP: SSP; 0:100, 25:75, 50:50, 75:25, and 100:0), phosphate solubilizing bacteria (PSB; with and without), and rhizobium (with and without) on chickpea growth and N and P uptake. RP:SSP ratios of 0:100 and 25:75 yielded higher plant height, growth rate, branch number, N concentration in straw and seeds, crude protein content, and P concentration and uptake in both straw and seeds compared to the 100:0 ratio. PSB application significantly improved chickpea growth, seed and straw N concentration, seed crude protein, and P uptake. Rhizobium-inoculated seeds also enhanced growth, N and P concentration in straw and seed, and P uptake. PSB enhanced rhizobium efficiency by promoting chickpea growth and increasing N and P concentration and uptake through solubilizing low-availability P from RP and SSP. Using RP:SSP (25:75) with PSB and rhizobium is recommended for enhanced chickpea growth and nutrient uptake in calcareous soils.