Impacts of nitrogen management and organic matter application on nitrous oxide emissions and soil organic carbon from spring maize fields in the North China Plain

Abstract Soil carbon dioxide (CO2) and nitrous oxide (N2O) emissions and carbon (C) sequestration are important processes for determining net greenhouse gas (GHG) emissions from maize fields. Farming management practices (FMPs) substantially affect crop productivity, soil organic carbon (SOC), and N2O emissions. However, relative knowledge is not sufficient, and further research is required for sustainable agriculture development. A multi-year experiment was performed on a spring maize field in the North China Plain (NCP) to quantify changes in SOC stocks, N2O emissions, and maize yields. Seven treatments were involved in the experiment, including no N fertilization (CK), farmers’ conventional N fertilization (FP), sole application of manure N (M), a combination of M and FP (MFP), FP combined with returned maize straw (SFP), fertilization with reduced synthetic N amount (RN), and fertilization with both reduced synthetic and manure N (RMN). The field measurements demonstrated that urea applications and returned maize straw increased N2O emission. The seasonal total N2O emissions under FP were significantly (P