Water-Use Efficiency of Crops in the Arid Area of the Middle Reaches of the Heihe River: Taking Zhangye City as an Example

Abstract

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.

The role of human activities in the weakening of the propagation relationship between meteorological and hydrological droughts in the Heihe River Basin

“…The effects were more significant from late spring to autumn. The cultivated land of the Heihe River Basin is mainly concentrated in the midstream region, where agricultural water use accounts for more than 90% of total water consumption (Xiao et al, 2019). In addition, crop water demand is the highest during summer and autumn, and irrigation water use has increased greatly in recent years (Gui et al, 2022), significantly reducing the correlation between meteorological and hydrological droughts.…”

Water Use Efficiency: A Review of Contextual and Behavioral Factors

“…The regional economy also influences technical factors, such as training, investment in infrastructure or ability to acquire water savings devices (Bruneau et al, 2013). Several economic activities, such as agriculture, depend on water to produce goods, and its productivity is often associated with average income of the producers Khair et al, 2019;Xiao et al, 2019), and diversification of the economy. For instance, if irrigated agriculture is the only source of livelihood (i.e., lack of diversification), water users will focus solely on increasing production to increase profits (Roobavannan et al, 2017;Khair et al, 2019), leading to a higher water demand (Ghanim, 2019;Xiao et al, 2019).…”

“…Several economic activities, such as agriculture, depend on water to produce goods, and its productivity is often associated with average income of the producers Khair et al, 2019;Xiao et al, 2019), and diversification of the economy. For instance, if irrigated agriculture is the only source of livelihood (i.e., lack of diversification), water users will focus solely on increasing production to increase profits (Roobavannan et al, 2017;Khair et al, 2019), leading to a higher water demand (Ghanim, 2019;Xiao et al, 2019). In such cases, users may not adopt techniques to increase WUE if water is not appropriately priced, or may adopt low flow high-efficiency faucets like drip irrigation but still consume more water (so called efficiency paradox), since their perception of well-being is driven by profit maximization.…”

“…Therefore, water users and institutions have taken actions toward improving water use efficiency (WUE) (Bruneau et al, 2013). Global and local policies, aiming at reducing water demand, have focused mainly on two sectors with a relatively high number of users and relevant for water security: households (Attari, 2014;Manouseli et al, 2019), and farmers (Bruneau et al, 2013;Tang et al, 2013;Chang et al, 2016;Roobavannan et al, 2017;Benito et al, 2019;Ghanim, 2019;Xiao et al, 2019), farmers being the biggest water user. Actions include installation of water-saving devices, leakage control, water re-use, water harvesting, implementation of indicators like non-revenue water (NRW), and the extension of economic incentives to users, such as increasing water price, and subsidies to water savers (Wang et al, 2015;Chang et al, 2016).…”

Water-Saving Potential of Different Agricultural Management Practices in an Arid River Basin

“…The Heihe River Basin (HRB) is the second largest inland river basin in China, where competition between agricultural and ecological water use is becoming keener. The Zhangye Basin, the middle reach of the HRB, has intensive agricultural activities that mostly rely on irrigation, consumes more than 80% of water, and contributes most of the agricultural production of the whole basin [46,47]. Due to limited water resources and low irrigation water-use efficiency, the Zhangye Basin faces great challenges in food security and water resource sustainability [48].…”