Impact assessment of the farming–breeding–bioenergy integrated system on agricultural greenhouse gases in Northeast China

In this study, we constructed an integrated framework of a farming–breeding–bioenergy system to estimate the greenhouse gas (GHG) emission inventories of various farming and breeding processes in the northeast region of China from 2000 to 2021 based on life cycle assessment. Then, we compared the emission differences between the farming–breeding–bioenergy integrated system and the traditional farming–breeding system in different production segments. Finally, we assessed the environmental impact of the integrated system on agricultural GHG emissions. Results showed that the main sources of GHG emissions in Northeast China include enteric fermentation, fertilizer application, crop energy reduction, crop cultivation, and manure management. Emission hotspots also showed a trend of shifting from south to north and from east to west. In terms of environmental impact intensity, the largest increase in environmental impact intensity values among the farming and breeding systems was recorded in Heilongjiang Province (0.36) and Inner Mongolia (0.13), respectively. In terms of mitigation effects, the farming and breeding systems showed a considerable amount of residual straw and manure that can be fed into bioenergy systems, at 1 801.47 and 394.12 Mt, respectively. The farming–breeding–bioenergy integrated system demonstrated mitigating effects on agricultural GHG emissions.