Integration of organic amendments and phosphate-solubilizing bacteria improves wheat growth and yield by modulating phosphorus availability and physiological reponses

Abstract

Saline calcareous soil presents significant challenges for crop production due to its poor nutrient availability and adverse effects on plant growth. Hence this study aimed to investigates the impact of integrating organic amendments—specifically Moringa seed residues, biogas manure, and vermicompost (Ver)—with and without phosphate-solubilizing bacteria (PSB), alongside two types of phosphatic fertilizers, ordinary super phosphate (OSP) and rock phosphate (RP), on the growth, yield, and nutrient uptake of wheat plants in saline calcareous soil conditions. The results indicate that the combined application of Ver + PSB, particularly when paired with OSP, consistently yields superior outcomes across all measured parameters, followed by Ver + PSB with RP. Notably, the Ver + PSB with OSP treatment exhibits the highest values across several key parameters: chlorophyll levels (chlorophyll a at 1.8, chlorophyll b at 0.84, and carotenoids at 0.72 mg g−1f wt), proline at 38.5 μg g−1 DW, relative water content at 80.76%, membrane stability index at 67.62%, as well as net photosynthetic rate (Pn), transpiration rate (Tr), and stomatal conductance (gs). Furthermore, this treatment showcases the highest antioxidant enzyme activities (Superoxide dismutase, SOD at 9.27 A564 min−1 g−1 protein, Catalase, CAT at 78.53 A564 min−1 g−1 protein, Peroxihdase, POX at 1.86 A564 min−1 g−1 protein), as well as NPK content and uptake in wheat straw and grains. Additionally, it leads to significant increases in wheat growth parameters, including plant height, straw weight, grain weight, 1000 grain weight, and protein content. However, it also results in a notable decrease in other parameters such as total soluble sugars and nonenzymatic antioxidants (Ascorbate, AsA; Total glutathione, GsH; and α-Tocopherol, α-TOC).