Cropping diversification increases microbial network complexity associated with enhanced soil multifunctionality and resistance to global change

While diversified cropping is widely known to improve soil functions, the specific microbial mechanisms driving soil multifunctionality and its resistance to climate-related disturbances remain poorly understood under global change scenarios. In this study, based on a 10-year field experiment with five cropping regimes (continuous maize and alfalfa monocultures, intercropping, double cropping, and three‑crop rotation), we quantified soil multifunctionality and its resistance to simulated warming and wetting–drying cycles, and linked these responses to microbial phylogenetic diversity, community composition, and co-occurrence network topology. Diversified cropping enhanced both multifunctionality and its resistance compared to those observed under continuous monoculture. Moreover, diversification was linked to shifts in bacterial and fungal α- and β-diversity and with higher microbial network complexity; the latter showing stronger relationships with multifunctionality than diversity alone. Diversified cropping systems enriched distinct fungal and bacterial taxa, which were positively linked to soil multifunctionality and its resistance to climate stress. The inoculation of microbial communities from high‑functioning soils into monoculture soils was associated with increases in soil multifunctionality and resistance, suggesting a potential contribution of microbial interactions to these functions. Overall, our findings highlight network-driven microbial reassembly as a potential pathway by which cropping diversification fosters climate-resilient agricultural ecosystems. • Diversified cropping increased soil multifunctionality and its resistance. • Microbial network complexity outperformed diversity in multifunctionality predictions. • Fungal communities outweighed bacterial communities in sustaining soil multifunctionality and its resistance. • Community inoculation restored multifunctionality and its resistance in monoculture soil.