农田连续免耕对甲烷氧化菌及甲烷减排的影响OA

No-tillage agriculture effectively reduces methane emissions from soil,but the impact of continuous no-tillage on methane emissions remains unclear.This study investigated farmland soils in Wenling City,Zhejiang Province,China,by analyzing surface soil samples from fields with four different no-tillage years.We examined the differences in methane emission flux,methane oxidation rate,and the relative abundance,community composition,and diversity of methane-oxidizing bacteria under varying continuous no-tillage years.By integrating soil physicochemical factors,we identified key environmental factors influencing methane reduction in continuously no-tillage soils.The results show that continuous no-tillage within a certain period effectively reduces methane emission flux while increasing the methane oxidation rate and the relative abundance of methane-oxidizing bacteria in soil.In conventionally tilled soils,Type Ⅰ methane-oxidizing bacteria(Methylococcaceae)dominate,whereas Type Ⅱ methane-oxidizing bacteria(Methylocystaceae)prevail in no-tillage soils.Organic matter and ammonium nitrogen content show significant positive correlations with methane-oxidizing bacteria abundance,particularly with the relative abundance of Type Ⅱ methane-oxidizing bacteria(Methylocystaceae),but a negative correlation with the relative abundance of Type Ⅰ methane-oxidizing bacteria(Methylococcaceae).These findings indicate that organic matter and ammonium nitrogen are key environmental factors influencing methane-oxidizing bacteria community structure and methane emissions in continuous no-tillage soils.These findings provide a theoretical basis for formulating farming practices that reduce greenhouse gas emissions in agricultural ecosystems.