Phosphate Solubilizing Microorganisms Increase Soil Phosphorus Availability: A Review

Phosphorus (P) availability in soil is often limited, posing a challenge for sustainable agricultural production. Phosphate solubilizing microorganisms (PSMs) have emerged as a promising biological approach to enhance soil P availability while minimize negative environmental impacts. Exploring the impact of PSMs on increasing soil available P is crucial for optimizing the utilization of insoluble P in soil and promoting sustainable agricultural practices. In this article, we provide a comprehensive review on the dynamics of soil available P, including its input, loss and transformation processes. Additionally, we draw a conclusion about how PSMs increase the availability of P in soil, including solubilizing inorganic P (Pi) and organic P (Po) by secreting substances such as protons, organic acids, inorganic acids, exopolysaccharides, hydrogen sulfide, siderophores and phosphatases. Notably, the factors influencing the P solubilizing activity of PSMs in soil are thoroughly discussed. Moreover, practical applications of PSMs for increasing soil P availability are summarized. Future research should focus on exploring novel PSM isolates, conducting long-term field experiments to assess the effects and potential risk of PSMs under diverse conditions, and investigating synergistic approaches with other P activators or beneficial microorganisms. This review will advance our understanding of PSMs and their practical application, enabling their widespread adoption in agricultural systems.