Integrated agronomic practice management decreases soil carbon emission and increases environmental ecological benefits of summer maize

Integrated agronomic practice management (IAPM) is an effective strategy for increasing nitrogen (N) use efficiency (NUE) and yield during crop production. Although various studies have evaluated the mechanism of a single agronomic management practice to increase yield and production efficiency and decrease environmental costs, few have investigated the effects of IAPM systems. A field experiment was conducted using four IAPM systems, a local smallholder farmers' practice system (T1), an improved management system (T2), a high-yield production system (T3), and an optimized management system (OMS), to study the annual yield, greenhouse gas (GHG) emissions, carbon (C) footprint (CF), and net environmental ecological benefit (NEEB) of summer maize. The results revealed that OMS was the most advantageous choice of IAPM, which increased yield and NUE and reduced GHG emissions and CF. Under OMS, yield and NUE were 42.6% and 88.1% higher, and N2O, CO2, and CH4 emissions were on average 35.4%, 5.8%, and 156.5% lower, respectively, than those under T1. Of the four IAPM systems, OMS resulted in the best soil quality, the lowest soil bulk density, the highest soil C/N ratio, and the highest soil total organic C content, which contributed to reduced GHG emissions. Carbon footprint and cost were the lowest under OMS, which decreased fertilizer input and GHG emissions. Optimized management system reduced CF and C cost by 5.9% and 33.9%, respectively, and increased NEEB by 111.4% compared to T1. Although T3 had the highest yield, it also had the highest GHG emissions and CF. In conclusion, OMS delivered a high yield and NUE while mitigating negative environmental impacts and increasing NEEB. Therefore, OMS is a suitable management system to increase the productivity and sustainability of summer maize.