The Effect of the Comprehensive Reform of Agricultural Water Prices on Farmers’ Planting Structure in the Oasis–Desert Transition Zone—A Case Study of the Heihe River Basin

The comprehensive reform of agricultural water prices is an important policy for promoting the high-quality sustainable development of agriculture and ensuring national water security. In this study, based on farmer survey data from different water price policy implementation areas in the oasis–desert transition zone of the Heihe River Basin (HRB), crops are divided into high-water-consuming crops and low-water-consuming crops based on the average water consumption per hm(2). The content of this study consists of two main parts: first, the study explores the response of farmers to different agricultural water price policies by comparing the impact of uniform water price and tiered water price policies on their planting structure. Second, it studies the areas where the tiered water price policy is implemented to verify the impact of price signals on farmers’ production decisions. The results show that, compared with the uniform water price policy, the implementation of the tiered water price policy will significantly reduce the proportion of high-water-consuming crops planted when other conditions remain unchanged. Under the tiered water price policy, the increase in water prices will reduce the proportion of farmers planting high-water-consuming crops, but the difference is not significant. This result reveals that when the opportunity cost of irrigation water increases, farmers will increase the proportion of low-water-consuming crops. The findings also indicate that a higher educational level, improved land inflow, the number of crop types, and satisfaction with the current subsidy policy will help increase the proportion of low-water-consuming crops. However, an increase in the family-cultivated land area will reduce the area of low-water-consuming crops.