Effects of Straw Returning Combined with Nitrogen Fertilizer on Soil CO2 Emission and Carbon Balance in Black Soil Maize Field

Field experiment was conducted in 2023 to investigate the effects of different straw returning methods with N fertilization on soil CO2 emission and carbon balance in black soil maize fields. The experiment included three straw return methods: straw leaving the field (S0, control), straw mulching returning to the field (S1), and straw rotary tillage returning to the field (S2), and two modes of N fertilization: regular N fertilizer application (N, 250 kg/hm2) and no N fertilizer application (W, 0 kg/hm2, control), totaling six treatments. The soil CO2 emission flux and the contents of soil organic carbon (SOC), dissolved organic carbon (DOC) and microbial biomass carbon (MBC) after maize harvest were measured under different treatments, and the relationship between soil CO2 emission and the contents of SOC, DOC, MBC were explored, and the carbon balance of black soil maize field ecosystem was analyzed. The results showed that the cumulative soil CO2 emissions in each treatment were S2N, S1N, S0N, S2W, S1W, S0W, and the cumulative soil CO2 emissions of S2N treatment were increased significantly by 70.31% compared with S0W treatment (P © 2024 Chinese Society of Agricultural Machinery. All rights reserved.