Isolation and Characterization of Peribacillus simplex NVC-PS3 for Reducing Nitrogen Fertilizer in Baby Maize

Excessive nitrogen fertilizer application in baby maize production can contribute to nutrient losses and environmental degradation, highlighting the need for sustainable nutrient management strategies. This study aimed to isolate, characterize, and evaluate the plant growth-promoting potential of an indigenous endophytic bacterium, Peribacillus simplex strain NVC-PS3, for reducing nitrogen fertilizer requirements in baby maize. P. simplex NVC-PS3 was identified based on morphological, physiological, biochemical, and 16S rRNA gene characteristics and evaluated for nitrogenase activity and nitrogen accumulation. Its effects on baby maize growth and yield were subsequently assessed under four urea application rates (350, 263, 175, and 0 kg urea ha−1) using a randomized complete block design with four replications. P. simplex NVC-PS3 exhibited high physiological adaptability, nitrogenase activity, and continuous nitrogen accumulation during cultivation. Seed inoculation improved soil fertility indicators, including soil organic matter, total nitrogen, available phosphorus, exchangeable potassium, and bacterial abundance. Inoculated plants also showed enhanced vegetative growth, chlorophyll content, biomass production, yield components, marketable yield, and nutritional quality. Notably, inoculation combined with a 25% reduction in urea application resulted in agronomic performance that did not differ significantly from that obtained with the full recommended urea rate. This finding suggests the potential of P. simplex NVC-PS3 to partially reduce synthetic nitrogen fertilizer inputs while maintaining crop productivity under the conditions of this experiment. However, further studies involving isotopic N tracing and quantitative assessment of biological nitrogen fixation are required to confirm the contribution of N2 fixation and validate the fertilizer-reduction potential of this strain.