Effect of inoculation with phosphate solubilizing fungus on growth and nutrient uptake of wheat and maize plants fertilized with rock phosphate in alkaline soils

To enhance the fertilizer value of rock phosphate in alkaline soils, the phosphate (P) solubilizing fungus Penicillium oxalicum was isolated from the rhizosphere soil of rock phosphate mine landfills and tested for its efficacy to solubilize rock phosphate (RP) as well as promotion of the growth of wheat and maize plants grown in soil amended with RP. The results showed that P. oxalicum effectively solubilized RP in Pikovskaya’s medium and released higher amount of phosphorus. The solubilization was increased with increase in concentration of RP. Field experiments showed that inoculation of P. oxalicum significantly increased the growth and yield of two consecutive crops i.e. wheat and maize compared to the control soil. The P content was significantly increased in the plants. The available P and organic carbon levels increased in RP amended soil inoculated with P. oxalicum compared to the control soil. It was found that the P. oxalicum along with RP can substitute the chemical fertilizer in alkaline soil and help in improving the crop production.

Research highlights
► Reports on utilization of rock phosphate (RP) as fertilizer in alkaline soils is limited in alkaline soils.
► The effect of P solubilizing fungus in RP amended alkaline soil was studied for two consecutive crops.
► Inoculation of P. oxalicum improved the available P levels in alkaline soil amended with RP.
► The yield of wheat and maize and the P content in plants significantly improved due to P. oxalicum.
► P. oxalicum along with RP can substitute the chemical fertilizers in alkaline soils.