Grain self-sufficiency versus environmental stress: An integration of system dynamics and life cycle assessment

Developing a sustainable grain supply is essential, especially in China. However, most previous research adopted a static approach to assess the environmental impacts of grain production, and such an approach focuses only on the product supply chain. An integrated system dynamics and life cycle assessment model was employed in this study to estimate and simulate the long-term performance of China's grain system from 2009 to 2030 from a holistic and dynamic perspective. Results showed that the fossil depletion of China's current 1 t of grain production per year was 1.11 × 104 MJ, which was mainly attributed to fertilizer production. For water footprint, the human health impact was 4.85 × 10−4 DALY/t, in which the water consumption contributed almost 77%, while the ecosystem quality impact was 7.86 × 10−6 species. yr/t, overwhelmingly derived from water pollution. Simulation results showed that the environmental impacts of China's grain production will increase by at least 19% in 2030 compared with the current situation if current development modes remain unchanged. Considerable benefits were observed in the integrated scenario, which would decrease the footprint results by up to 27% while increasing the self-sufficiency rate by 10%. Scenario analyses indicated that adopting measures from the production and consumption perspectives (e.g., simultaneously adjusting planting structure, increasing rural investment, reducing fertilizer application, and modifying diet structure) could effectively mitigate the environmental burdens while enhancing food security. Moreover, promoting the development of agricultural water conservancy measures and renewable energy with high utilization rates is recommended to ameliorate the water scarcity impact and ensure sustainable agricultural development.