Crop Rotation and Fallowing and Associated Compensation Under the Principle of Determining Land Use by Water Availability: A Case Study of Yanchi County, Ningxia

Agricultural land use in arid regions is subject to binding water-resource constraints, yet existing studies of crop rotation and fallowing have focused mainly on cultivated-land restoration and crop production, with limited attention to spatial allocation and compensation under water constraints. This study develops a plot-level framework under the principle of determining land use by water availability. Taking Yanchi County, Ningxia, as a case study, ecological, water-resource, and land-resource constraints are integrated through spatial overlay and suitability assessment, and groundwater-, ecological-, and cultivated-land-protection schemes are developed. Results identify 9309 hm2 as potentially feasible for crop rotation and 4568 hm2 for fallowing. Under the high scenario with maize–potato rotation, irrigation-water reductions are 6.37, 4.69, and 4.31 million m3, with corresponding net-profit losses of 13.75, 9.53, and 9.60 million yuan, respectively. The groundwater-protection scheme achieves the largest absolute water savings and best matches current groundwater-management needs. Baseline compensation standards are 6357, 1390, and 615 yuan/hm2 for maize fallowing, maize–potato rotation, and maize–sorghum rotation, respectively. The findings support differentiated, phased implementation combined with loss protection and water-saving incentives.