Enhancing agricultural sustainability: Optimizing crop planting structures and spatial layouts within the water-land-energy-economy-environment-food nexus

In the new phase of sustainable development, agriculture is seeking sustainable management of the water-land-energy-economy-environment-food nexus. At present, there are few studies on optimizing crop planting structure and analyzing its spatial layout with consideration of natural and socio-economic factors. Herein, we proposed a framework for addressing this issue. In this framework, the NSGA-II algorithm was used to construct the multi-objective optimization model of crop planting structures with consideration of water and energy consumption, greenhouse gas (GHG) emissions, economic benefits, as well as food, land, and water security constraints, while the model for planting spatial layout optimization was established with consideration of crop suitability using the MaxEnt model and the improved Hungarian algorithm. This framework was further applied in the Black Soil Region of Northeast China (BSRNC) for analyzing optimized crop planting structures and spatial layouts of three main crops (rice, maize, and soybean) under various scenarios. This study showed that the sown area of rice in the BSRNC decreased by up to 40.73 % and 35.30 % in the environmental priority scenario and economic-environmental balance scenario, respectively, whereas that of soybean increased by up to 112.44 % and 63.31 %, respectively. In the economic priority scenario, the sown area of rice increased by up to 93.98 %. Expanding the sown area of soybean was effective in reducing GHG emissions. On the contrary, rice production led to greater environmental costs though it provided higher economic returns. Among the three crops, maize exhibited an advantage in balancing environmental and economic benefits. Hegang-Jixi area in the northeast of the BSRNC was identified as the key area with the most intense crop planting transfer among different scenarios. Overall, this framework provides a new methodology for optimizing crop planting structures and spatial layouts with consideration of the nexus of various factors. Moreover, the case study demonstrates the applicability and expansion potential of the framework in the fields of sustainable agricultural development and food security assurance.