抄録
Soil organic carbon (SOC) stabilization in intercropping systems is increasingly recognized as a microbially mediated process, yet the mechanisms by which plant–plant interactions regulate rhizosphere microbial carbon transformation and microbial necromass formation remain unresolved. Using a long-term peanut–maize intercropping experiment, this study investigated peanut rhizosphere soils collected from zones adjacent to and distant from maize plants to elucidate how neighboring maize regulates microbial processes associated with SOC stabilization. Integrated analyses of microbial carbon metabolism, oxidative enzyme activity, microbial necromass carbon, soil respiration, and SOC demonstrated that maize proximity suppressed polyphenol oxidase activity while enhancing microbial carbon metabolic capacity, substrate utilization diversity, microbial necromass carbon accumulation, and SOC storage, without altering soil respiration. Mechanistically, SOC stabilization was driven primarily by improved microbial carbon-use efficiency and enhanced conversion of plant-derived carbon into persistent microbial necromass, rather than by increased carbon inputs or reduced carbon mineralization. These findings establish a mechanistic framework linking plant–plant interactions, microbial carbon metabolic reprogramming, microbial necromass formation, and SOC stabilization, providing new insights into the microbial carbon pump in agroecosystems and a theoretical foundation for designing intercropping systems that maximize long-term soil carbon sequestration.
