Closing economical and sustainability gaps for China's wheat, maize, and rice production: A county level energy analysis approach.

Abstract

China is facing simultaneous challenges in achieving food security, increasing smallholder farmer incomes, and reducing environmental pollution. Conducting spatially explicit analysis of the environmental sustainability and economic benefits of food production systems can assist policymakers in formulating context-specific strategies, yet previous studies have largely been conducted at national and provincial scales or have focused solely on one aspect of the environment or economy. Here, we use Emergy Analysis (EMA) and Energy Efficiency Cost (EEC) assessments to reveal notable spatial variations in the emergy sustainability index (ESI) and EEC for staple crop production at the county level in China, with ESI ranges for wheat, maize, and rice being 0.02-4.53, 0.04-3.57, and 0.05-3.40, and EEC ranges being 0.24-3.04, 0.09-4.38, and 0.12-4.38 CYN MJ^-1, respectively. Counties with high ESI and low EEC are mainly distributed in East, North, and Central China and benefit from higher grain yields and lower chemical inputs. In contrast, counties with low ESI and high EEC, located mainly in the Southwest, Northwest, and South regions, suffer from underutilization of natural resources, abuse of nitrogen fertilizer, and inefficient use of agricultural machinery. Closing these regional ESI and EEC gaps would benefit China as a whole and could likely be achieved the fastest by increasing grain yields and enhancing agricultural machinery efficiency, although improving nitrogen use efficiency (e.g., in Northeast, North, and Northwest China) could also make a notable contribution. In conclusion, our research provides a deeper understanding of the relationship between environmental and economic factors in China's staple crop production, thereby advancing sustainable food production. In addition, our study provides scientific support for policymakers to formulate optimal regional management strategies and offers guidance to farmers on more efficient production practices.