Improved Soil Phosphorus Availability and Lettuce Growth by a Mudflat-Derived Halotolerant Phosphate-Solubilizing Bacterium, Priestia aryabhattai JJ33, in Compost-Amended Soils

Phosphate-solubilizing bacteria (PSB) can enhance soil phosphorus availability and plant growth, but their effectiveness may vary depending on bacterial characteristics and compost type. However, the performance of halotolerant PSB in soils amended with different manure composts requires further evaluation. This study aimed to characterize a coastal mudflat-derived halotolerant PSB, Priestia aryabhattai JJ33, and evaluate its effects on phosphorus mobilization and lettuce growth in soils amended with different manure composts. Cattle, swine, and poultry manure composts were inoculated with strain JJ33 and combined with standard chemical fertilization. Soil phosphorus availability, plant growth, and post-harvest soil chemical properties were evaluated after 31 days of lettuce cultivation. JJ33 inoculation significantly enhanced soil phosphorus availability and plant growth compared with uninoculated compost treatments. Among all treatments, poultry manure compost inoculated with JJ33 (PMP) produced the highest fresh weight (42.7 g plant−1) and soil available P2O5 (446 mg kg−1), representing 67% and 41% increases over the NPK control, respectively (p < 0.05). Strain JJ33 also exhibited strong phosphate-solubilizing activity under moderate salinity conditions, converting insoluble phosphate into plant-available forms. Its physiological characteristics indicate broad adaptability to diverse soil environments, including salt-affected soils, and support its potential application as a biofertilizer for sustainable nutrient management and crop production.