Abstract

Phosphorus (P) availability is a critical factor limiting plant growth, particularly under drought conditions, where soil moisture deficits impair nutrient uptake. This article investigates the role of phosphorus-solubilizing microorganisms (PSMs) in enhancing P availability in agricultural soils under drought stress. Field and laboratory experiments were conducted across Mediterranean and semi-arid soils to assess microbial activity, P solubilization rates, and plant growth responses. Results showed that drought-tolerant PSMs, such as Bacillus and Pseudomonas species, increased soluble P by 20–35% under water-limited conditions compared to controls. Soil enzyme activities and microbial biomass were reduced under drought but partially mitigated by PSM inoculation. These findings highlight the potential of PSMs to improve P availability and support crop resilience in water-stressed environments, offering insights for sustainable agriculture in drought-prone regions.