Boosting maize yield and root traits with salt-tolerant plant growth-promoting rhizobacteria in the Indo-Gangetic plain: A microbial solution to soil salinity

Soil salinity, which significantly reduces maize production in the Indo-Gangetic plains, requires continuous and sustained efforts. This study investigated six salt-tolerant bacterial strains and their ability to promote maize growth, yield, and root architecture in saline conditions. Among them, Bacillus subtilis ASM7 and Pseudomonas fluorescens ASM16 were the most effective, markedly enhancing plant height, dry matter accumulation, and yield attributes such as grain yield by 27% and 23%, respectively. These strains also improved cob traits and root architecture, such as root length and root volume by 77% and 56%, respectively, particularly by stimulating finer root structures that favor more efficient soil exploration under stress. The findings highlight the preferential stimulation of finer root structures over primary development, which optimizes soil exploration during stress. All these results of plant growth-promoting rhizobacteria in saline agro-ecosystems show that B. subtilis ASM7 and P. fluorescens ASM16 strains act as important environmentally friendly bio-inoculants for maize cultivation in the long term, offering a novel microbial strategy for improving crop resilience and productivity in salt-affected agro-ecosystems.