The application of slow-release nitrogen fertilizer affected maize yield by regulating soil microbial diversity

Abstract In agro-pastoral interleaved zones, determining the appropriate rate of slow-release nitrogen fertilizer application is crucial in understanding the interplay in soil microbial community structure, network complexity, crop yield, as well as regional ecological security. Building upon a positioning experiment conducted previously, this study investigates six different gradients (N0, N8, N12, N16, N20 and N24) of nitrogen fertilizers, The results revealed that ALPT, NO3−-N and pH were the primary factors influencing the composition of bacterial communities.MBC, ALPT, and HR played a significant role in shaping fungal community composition. Proteobacteria, Acidobacteriota, and Myxomycota were identified as the dominant bacterial phyla affecting yield, while Basidiomycota and Glomeromycota were the key fungal phyla involved. Application of slow-release nitrogen fertilizer led to an increase in Actinobacteria and Bacteroidota abundance in both rhizosphere soil and non-rhizosphere soil. Ascomycota and Basidiomycota relative abundances exhibited spatial variations. Nitrogen improved soil physical and chemical properties ss and regulated microbial community composition, which effectively enhanced maize yield. Nitrogen fertilizer reduced bacterial network complexity but enhanced fungal network complexity and stability. It not only simplified the bacterial network but also enhanced the abundance of beneficial bacteria. This led to increased microbial activity, resulting in enhanced crop yields.