ALBERT

Description: The middle reaches of the Heihe River are an important food base in the arid regions of Northwest China. The agricultural water consumption in this region accounts for about 90% of the total water consumption. The shortage of water resources is the primary reason for restricting agricultural development. Therefore, studying the efficiency of agricultural water use is essential to improving the effective use of water resources. Under the premise of considering agricultural water saving, we improved the water efficiency model from the perspective of pure agricultural income that farmers are more concerned about. In this study, we took Zhangye City in the middle reaches of the Heihe River as an example, based on meteorological crop data and farmer survey data. Then, we used the input–output method to quantitatively analyze the net income of the crops in Zhangye City. We used the CROPWAT model to calculate the water demand of crops during the growing season. Lastly, we used the improved water-use efficiency (WUE) model to analyze WUE differences of crops in the study area. We reached the following conclusions: (1) among the six crops in the study area, the net profit of seed corn was 20,520 yuan/ha, followed by field corn, 11,700 yuan/ha, then followed by potato, rapeseed, wheat, and barley; (2) the maximum water requirement for the crop growth period was 597.2 mm for field corn, followed by 577.3 mm for seed corn, then followed by rapeseed, wheat, barley, and potato; (3) among the six crops, the WUE calculated using the water efficiency model before and after improvement had obvious differences. The WUE calculated using the original model reached 9.03 yuan/m3 for potato, followed by 6.33 yuan/m3 for seed corn. The WUE calculated using the improved model reached 3.44 yuan/m3 for seed corn, which is the maximum, followed by potato with 2.25 yuan/m3. Considering the agricultural water saving and crop yields, we propose to properly expand the cultivation of seed corn and potato in the middle reaches of the Heihe River. This would be more conducive to achieving a “win-win” situation for water conservation and revenue.