Enhancing Phyllostachys edulis seedling growth in phosphorus-deficient soil: complementing the role of phosphate-solubilizing microorganisms with arbuscular mycorrhizal fungi

Background and aims The addition of functional soil microbes to the soil can enhance the utilization of soil phosphorus (P) for plants, but the mechanisms underlying this process are not fully understood. The study aimed to investigate the effects of inoculating phosphate-solubilizing microorganisms (PSMs), with or without arbuscular mycorrhizal fungi (AMF), on Phyllostachys edulis seedling growth in soils with varying P levels.Methods The pot experiment was conducted on P. edulis seedings with inoculation treatments of a mixture of 15 PSMs from the P. edulis rhizosphere alone, or PSMs in cooperation with AMF. Plant mass and nutrient concentrations, soil properties and soil microbial communities were assessed when the seedlings had completed their first-year growth spurt (T1) and second-year growth spurt (T2).Results The application of PSMs, particularly in combination with AMF, resulted in significant increases in seedling mass and nutrient content under P-deficient conditions, accomplished through modifications in soil nutrient concentrations and enzyme activities related to nitrogen, carbon, and P metabolism. The beneficial outcomes were accompanied by alterations in the composition and interactions within the constituents of the rhizosphere microbial community. Remarkably, the co-inoculation of AMF and PSMs led to a higher abundance of microorganisms that promote plant growth within the rhizosphere.Conclusion The utilization of PSMs, especially in combination with AMF, proves to be an effective strategy for enhancing P. edulis seedlings growth during their second-year growth, particularly in P-deficient soil. This approach modifies the soil microenvironment, offering a promising avenue for improving soil P utilization by woody plants.