How can agricultural water use efficiency be promoted in China? A spatial-temporal analysis

China's agricultural sector experienced rapid growth in the last two decades, with a tripled increase in sectorally total economic output from 2000 to 2017. However, expanding large-scale production also leads to substantial consumption of water resources. Using the panel data of China's 31 provinces from 2000 to 2015, this study adopts the stochastic frontiers analysis model to measure the country's agricultural water use efficiency (AWUE). We also develop a spatial econometric model to identify the main factors that influence AWUE. The results show that the AWUE of each province ascended during the observation period, presenting obvious spatial correlations and unbalanced development at the provincial level. The per capita disposable income of rural households and the proportion of high school or above education are key influencing factors of AWUE. Additionally, factors such as the total sown area of crops, the total storage capacity of reservoirs, and the number of water-saving machines, electric and diesel motors also exert certain influences. Therefore, improving the rural residents' income and the educational level of practitioners, promoting the scale of arable land, providing training for water-saving technology, and deploying water-efficient irrigation equipment can contribute to the sustainable agriculture of China.