Grass mulching, an orchard management practice that cultivates herbaceous vegetation in inter-row spaces as living cover or green manure, profoundly influences the soil microbiome, whose assembly is tightly coupled with management regimes. Nevertheless, assessments of how grass mulching modulates soil microbial communities and soil fertility across topographic positions in hilly peach orchards remain scarce. In this study, we established a field experiment employing Vicia villosa Roth var. glabrescens as the mulching species in a representative peach ( Prunus persica ) orchard on hilly terrain. High-throughput amplicon sequencing was applied to systematically dissect the mechanisms underlying microbial community interactions. Relative to clean tillage, short-term grass mulching did not significantly alter total microbial species richness ( P > 0.05); however, it induced pronounced restructuring of the community, with a stronger effect on the fungal than on the bacterial fraction. Among fungi, Rozellomycota exhibited the most pronounced augmentation, increasing by 1936.62%, 13,889.96% and 8.38% at the upper, middle and lower slope positions, respectively. Within the bacterial domain, Methylomirabilota was the most responsive phylum, increasing by 9.73%, 79.24% and 16.80% across the same toposequence. Grass mulching enriched keystone taxa involved in soil C and N cycling, significantly enhancing soil fertility (mean increases: total C 24.6%, total N 44.3%; n = 3; P < 0.05). Collectively, our findings indicate that short-term grass mulching markedly accelerates the engagement of soil microbial communities in C–N cycling processes within hilly peach orchards.
Huang et al. (Sat,) studied this question.