Phosphate-Solubilizing Microorganisms: Mechanisms and Agricultural Applications

Phosphate-solubilizing microorganisms (PSMs) are widely recognized for their ability to convert insoluble soil phosphorus into bioavailable forms, thereby reducing dependence on chemical fertilizers and promoting sustainable agriculture. Despite phosphorus abundance in soils, its fixation in unavailable mineral complexes poses a persistent challenge for crop production, emphasizing the need for biological solutions. This review synthesizes recent advances in PSM research, focusing on their diversity, ecological adaptations, and solubilization mechanisms, including organic acid production, enzymatic mineralization, and siderophore activity. A critical examination of field and greenhouse studies highlights variations in PSM efficacy under diverse soil types, environmental stresses, and cropping systems, while also identifying key formulation strategies to enhance microbial persistence and plant-microbe interactions. Comparative analysis of current literature reveals significant progress in understanding PSM-soil geochemistry interactions, yet demonstrates gaps in strain stability, large-scale application, and integration into precision agriculture. By consolidating mechanistic understanding with practical outcomes, this review underscores the novelty of PSM-based biofertilizer approaches and provides strategic recommendations to bridge laboratory-to-field translation, offering a pathway toward scalable, eco-friendly nutrient management solutions.