Targeted regulation of the microbiome by green manuring to promote tobacco growth

Green manuring is an established strategy for soil nutrient enrichment; however, its effects on the soil microbiome remain unclear. In this study, we assessed the impact of green manuring on soil microbial diversity, functional profiles, and enzymatic activities in a pot experiment involving tobacco rotation with three types of green manure: smooth vetch, ryegrass, and radish. Our data revealed distinct temporal shifts in bacterial communities under diverse tillage while fungi communities showed obvious clustering between fallow and green manuring. Moreover, green manure-sensitive bacterial and fungal taxa constitute a greater proportion of total sequences than their fallow-sensitive counterparts, indicating a more pronounced influence of green manuring on microbial communities. Functionally, green manuring augmented the relative abundance of N-cycle-related genes and was strongly associated with elevated N-acetyl-glucosaminidase activity. Notably, a subset of green manure-sensitive microbes exhibited significant antagonistic interactions with the fungal pathogens Fusarium spp. and Fusarium solani, and synergistic interactions with the beneficial bacteria Pseudomonas spp. Collectively, these findings suggest that green manuring promotes an optimized soil environment characterized by efficient nutrient cycling and diminished pathogenicity, thereby providing a scientific basis for targeted microbiota manipulation in agricultural systems.