Cover crop diversity generates complex rhizo-microbiome networks by improving soil properties

Agricultural soils face significant microbial disruption due to chemical inputs and continuous cropping. Cover crops offer a potential strategy to restore soil microbial health, yet the influence of cover crop species richness on root and rhizosphere microbiomes remains poorly understood. In this study, we evaluated the effects of six cover crop species, comparing monocultures and mixtures, to test the hypothesis that higher species richness enhances microbial diversity and network complexity via improved root coverage, carbon exudation, and soil properties. We found that microbial communities in species-rich mixtures exhibited greater community stability, abundance of plant beneficial bacteria, and network complexity than those under monocultures. Root microbiomes were primarily shaped by plant biomass and root traits, whereas, rhizosphere communities were influenced by species richness and soil organic carbon (SOC). Network analyses revealed that diverse cover crops enhanced microbial connectivity and function through synergistic plant-soil interactions. These findings highlight the potential of diverse cover cropping systems to foster resilient microbial networks and improve soil health.