Dilemma and solution of land scarcity, agro-production, and environmental risk for typical grain-producing areas in rapid urbanizing process in China.

How to satisfy food production sustainably in the rapid urbanizing process is a vital problem for major grain-producing areas. Taking two national grain-producing regions in China, Shandong and Dongting Lake Region as examples, this study uses step-by-step prediction and a double-objective linear programming model to analyze the dilemma of land scarcity, food demand, and environmental load. It is found that food demand by 2030 will induce partial regional cropland deficiency and heterogeneous agro-environmental risk among cities. The double-objective linear programming model finds possible solutions in different scenarios: on the premise of keeping the current cropland area unchanged, the upper threshold of crop yield by 2030 will be 2539.06 × 10 t in Dongting and 7175.13 × 104 t in Shandong, respectively. On the condition of guaranteeing food self-sufficiency and minimizing the environmental load, the lower threshold of arable land area should be 99.47 × 10 ha in Dongting and 436.85 × 10 ha in Shandong. Pollutant reduction will be realized by reallocation of agro-production task and optimized practices. The food carbon impact can be reduced by up to 1.27 kg CO eq/kg. This study contributes to feasible pathways towards adequate agro-production, lessened land scarcity, and minimal environmental risk for rapid urbanizing cities in a sustainable way.