Enhancing nutrient uptake efficiency in Zea mays: the role of plant growth-promoting bacteria in modifying root characteristics and mobilizing soil nutrients

BACKGROUND The use of plant growth-promoting bacteria (PGPB) is a promising approach to improving crop nutrient management. This study used multiple biological nutrient indicators to identify efficient PGPB strains and to investigate their impacts on soil nutrient dynamics, crop growth, and nutrient uptake during the critical growth stages of Zea mays. RESULTS Two high-performing PGPB strains were selected based on their phosphate solubilization and growth-promotion potential. Pot experiments revealed that these strains enhanced soil nutrient characteristics significantly, including soil organic matter, alkaline-hydrolyzable N, and available K, thereby improving nutrient availability. In Z. mays, these strains increased total root length, root diameter, and number of root tips markedly, expanding the root system's nutrient absorption capacity. Without phosphorus (P) fertilizer, nitrogen uptake efficiency (NUE) and potassium uptake efficiency (KUE) increased by up to 34% and 25.43%, respectively, compared to the control. With P fertilizer, the maximum increases were 65.37% and 33.33%. In the absence of P fertilizer, combined inoculation enhanced nutrient uptake efficiency more than single inoculation (T1, T2), with NUE increasing by 14.04% and 10.29%, and KUE by 9.61% and 7.35%, respectively. CONCLUSION Both single and combined PGPB inoculations effectively enhanced Z. mays root architecture and activated essential soil nutrients, highlighting their potential in a sustainable approach to improve nutrient management and crop productivity. (c) 2025 Society of Chemical Industry.