Role of Organic Matter and Phosphate Solubilizing Bacteria in Phosphorus Availability and Wheat Growth in Gypsum Soils

Phosphorus is one of the most abundant mineral elements found in the Earth's crust in both organic and inorganic forms. Although present in high concentrations, only 0.1% of total phosphorus is available for agriculture due to its poor solubility and availability. Thus, the present work aimed to study the effects of mixed organic fertilizers and Phosphate Solubilizing bacteria (PSB) (i.e., Bacillus megaterium, Bacillus polymyxa, and Bacillus subtilis) to enhance the efficiency of wheat crop phosphorus availability in gypsiferous soil. The experiment was conducted in the field conditions using seven different fertilizers and PSB combinations. The wheat grain content of total phosphorus increased significantly in mineral fertilizer + organic fertilizer + PSB treatments by 45%, and in organic fertilizer + PSB by 41%, as compared to the control variant. There was also an increase in the total phosphorus content of the wheat straw, as well as in the weight of wheat grains. The treatments, i.e., T7 (mineral + organic fertilizer + PSB), T4 (mineral + organic fertilizer), and T6 (organic fertilizer + PSB) were significantly superior to the rest of the treatments in the case of P enrichment and wheat growth. The percentage increase in the weight of 1000 grains compared to the control was 29%, 24%, and 22%, respectively, for T7, T4, and T6 treatment. The results indicated that the use of PSB with mineral and organic fertilizers could improve the P availability to plants for sustainable crop cultivation in gypsum rich soils.