Effect of Bacillus licheniformis on phosphorus use efficiency in soybean crops

Abstract

Abstract Soybean has significant importance in the global agricultural sector. However, yield is often compromised by the low availability of phosphorus in the soil. The inoculation of phosphate-solubilizing bacteria has shown promise in increasing the absorption of this nutrient. Therefore, this study aimed to evaluate the efficiency of Bacillus licheniformis as a phosphorus solubilizer, as well as to investigate its impact on soybean crop development. The experimental design was a randomized block design arranged in a 4x2 factorial scheme, with four replications. Treatments consisted of four phosphate fertilization rates (0, 40, 60, and 80 kg ha−1 P2O5, applied as single superphosphate and equivalent to 0, 50%, 75%, and 100% the recommended rate) associated or not with inoculation with Bacillus licheniformis. Morphological variables (plant height, root length, stem diameter, and branch number) and yield components (pods per plant, seeds per plant, seeds per pod, thousand grain weight, and grain yield) were determined. There were no significant effects of biological inoculation or phosphorus rate on morphological characteristics or some yield components, attributed to the high content of available phosphorus in the experimental soil (39.3 mg dm−3). On the other hand, inoculation with B. licheniformis significantly increased thousand grain weight and grain yield, even under high phosphorus availability. Regression analysis indicated that both variables had a positive linear response to phosphorus rate. These results reinforce the agronomic potential of B. licheniformis as a complementary technology to phosphate fertilization, contributing to the sustainability of soybean production.