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Addressing concerns about mitigating greenhouse gas(GHG) emissions while maintaining high grain yield requires improved management practices that achieve sustainable intensification of cereal production systems.In the North China Plain,a field experiment was conducted to measure nitrous oxide(N_2O) and methane(CH4) fluxes during the maize(Zea mays L.) season under various agricultural management regimes including conventional treatment(CONT) with high N fertilizer application at a rate of 300 kg N ha~(-1) and overuse of groundwater by flood irrigation,optimal fertilization 1 treatment(OPTIT),optimal fertilization 2 treatment(OPT2T),and controlled-release urea treatment(CRUT) with reduced N fertilizer application and irrigation,and a control(CK) with no N fertilizer.In contrast to CONT,balanced N fertilization treatments(OPT1T,OPT2 T,and CRUT) and CK demonstrated a significant drop in cumulative N_2O emission(1.70 v.s.0.43-1.07 kg N ha~(-1)),indicating that balanced N fertilization substantially reduced N_2O emission.The values of the N_2O emission factor were 0.42%,0.29%,0.32%,and 0.27%for CONT,OPTIT,OPT2 T,and CRUT,respectively.Global warming potentials,which were predominantly determined by N_2O emission,were estimated to be 188 kg CO_2-eq ha~(-1) for CK and 419-765 kg CO_2-eq ha~(-1) for the N fertilization treatments.Global warming potential intensity calculated by considering maize yield was significantly lower for OPT1 T,OPT2T,CRUT,and CK than for CONT.Therefore,OPT1 T,OPT2T,and CRUT were recommended as promising management practices for sustaining maize yield and reducing GHG emissions in the North China Plain.
Addressing concerns mitigating greenhouse gas (GHG) emissions while maintaining high grain yield requires management practices that achieve sustainable intensification of cereal production systems. The North China Plain, a field experiment was conducted to measure nitrous oxide (N2O) and methane (CH4 ) fluxes during the maize (Zea mays L.) season under various agricultural management regimes including conventional treatment (CONT) with high N fertilizer application at a rate of 300 kg N ha ~ (-1) and overuse of groundwater by flood irrigation, optimal fertilization 1 treatment (OPTIT), optimal fertilization 2 treatment (OPT2T), and controlled-release urea treatment (CRUT) with reduced N fertilizer application and irrigation, and a control (CK) with no N fertilizer. fertilization treatments (OPT1T, OPT2 T, and CRUT) and CK demonstrated a significant drop in cumulative N 2 O emission (1.70 vs 0.43-1.07 kg N ha -1), indicating that balanced N fertilization subs tantially reduced N_2O emission.The values of the N_2O emission factors were 0.42%, 0.29%, 0.32%, and 0.27% for CONT, OPTIT, OPT2 T, and CRUT, respectively. Global warming potentials, which were predominantly determined by N_2O emission, were estimated to be 188 kg CO 2 -eq ha -1 for CK and 419-765 kg CO 2 -eq ha -1 for the N fertilization treatments. Global warming potential intensity calculated by considering maize yield was significantly lower for OPT1 T, OPT2T, CRUT, and CK than for CONT. Before, OPT1 T, OPT2T, and CRUT were recommended as promising management practices for sustaining maize yield and reducing GHG emissions in the North China Plain.