Regulation of soil microbiota and maize growth by siderophore-producing bacteria in Alfisol

Abstract Plant growth-promoting rhizobacteria (PGPR) widely improve plant growth. Siderophore-producing bacteria (SPB) are a valuable PGPR type worthy of in-depth exploration. In this study, five SPB strains were selected as the research subjects. Pot experiments were conducted to evaluate their impact on maize growth in Alfisol. It was observed that the five SPB strains improved maize growth and nutrient uptake to varying degrees. Among them, CNRSB01 had the most significant effect. Compared with the control, CNRSB01 raised maize P, K, Ca, Mg, Fe, Mn, Cu and Zn content by 27.33%, 45.60%, 15.78%, 13.12%, 40.63%, 30.81%, 31.39% and 38.23%, respectively. Maize dry weight in the CNRSB01 treatment increased by 93.45%. Soil invertase activity and soil phosphatase activity in the CNRSB01 treatment increased by 39.12% and 29.04%, respectively. It also revealed that SPB modified soil bacterial diversity. Both Simpson index and Shannon index of CRSB02 and CNRSB01 treatments were significantly different from the control. PCA analysis showed that CNRSB01 treatment had the most divergent bacteria community composition. Research results suggested that SPB promote maize growth and nutrient uptake primarily by optimizing the soil microenvironment. These results provide theoretical reference for microbial application to enhance crop growth.