Crop Redistribution Increases Regional Production While Reducing Water Deficit, Fertilizer Use, and Production Losses: Evidence from a Multi-Objective Optimization at the County Level in Northeast China

Given the increasing crop yield losses, water scarcity, and fertilizer application in Northeast China, a systematic assessment is increasingly necessary to investigate the potential of crop redistribution to enhance grain production while alleviating environmental pressures. Here we quantify the potential of crop redistribution in Northeast China through a multi-objective optimization approach. First, we construct a dataset that contains four objectives including crop yield, yield losses, water deficit, and nitrogen fertilizer application based on their annual data in 273 counties over two decades (2001–2020). Second, we optimize the county-level distribution of rice, maize and soybean using the developed dataset and evaluate the benefits on each objective. Finally, we design a crop redistribution scheme and analyze its impact on the cropping structure in Northeast China based on the optimal solution. Results show significant potential of crop redistribution, with crop production increases by 1.70% (2.41 × 106 tons), production losses decrease by 2.69% (1.84 × 105 tons), water deficit decreases by 6.78% (3.88 × 108 m3) and N fertilizer application decreases by 10.87% (5.41 × 107 kg) when all the objectives are optimized simultaneously. The crop redistribution scheme is summarized as follows: compared with the baseline crop structure, rice area increases by 69.58%, maize reduces by 12.8%, and soybean reduces by 54.79% in Northeast China. Specifically, rice area increases in northwestern Heilongjiang, eastern Jilin, most counties in Liaoning, and reduces elsewhere. Maize area reduces in most of the counties, except for several counties in southwestern Heilongjiang, northern Jilin, and northern parts of the Four Eastern Leagues. Soybean area reduces in northern part of Heilongjiang and Four Eastern Leagues and increases in western Jilin and most counties in Liaoning. Although crop redistribution scheme was generated, the model remains limited in terms of crop types, spatial resolution, and the range of factors influencing crop distribution. Future work will address these limitations to enhance the reliability and applicability of the crop redistribution model.