Phosphate-solubilizing Inoculant Improves Agronomic Performance of Common Bean with Reduced Phosphate Fertilizer dose

Phosphorus is an essential nutrient for cell division and the development of the growing tip of the plant, and its availability in the soil is critical to ensure common bean productivity. Phosphate-solubilizing bacteria (PSB) can increase the availability of phosphorus in the soil. Then, we hypothesized that PSB inoculant could improve the agronomic traits of common bean under field conditions. Thus, this study aimed to evaluate the agronomic performance of the common bean inoculated with a phosphate-solubilizing inoculant under different growing seasons and edaphoclimatic conditions.Four field experiments, carried out in three different locations, in two growing seasons within two consecutive agricultural years, were addressed to a randomized block design with five replicates and seven treatments, including: Absolute control (AC), 50% phosphate fertilization (AF50B0), full-dose phosphate fertilization (AF100B0), and four treatments with different doses of the phosphate-solubilizing inoculant in combination with 50% phosphate fertilization, namely 1 mL (AF50B1), 2 mL (AF50B2), 3 mL (AF50B3), and 4 mL (AF50B4) per kg of seeds. Root and shoot development, yield components, P accumulation in grains, and productivity were determined. The phosphate-solubilizing inoculated treatments showed significant effects on the evaluated parameters, with AF50B4 standing out as a significant influence on growth and production parameters. In general, P accumulation in grains on AF50B4 was greater than that of the AF100B0 treatment. In terms of productivity, across the four locations, the AF50B4 treatment yielded 4,111 kg ha^-1, compared to 3,496 kg ha^-1 in the AF100B0 treatment, representing a 17.6% increase. The phosphate-solubilizing inoculant, especially at a dose of 4 mL kg^-1 seed, promotes improvement in growth and yield components, providing increased grain yield and P accumulation in common bean.