Impact of climate change on water use efficiency by wheat, potato and corn in semiarid areas of China

• The drought trend in China's semiarid areas has intensified over the past 50 years.
• This study investigated the effects of climate change on crop water use efficiency.
• The water use efficiency by crop has significantly increased over the past 50 years.

Our objective was to elucidate the effects of climate change on crop water use efficiency in the northwest semiarid area of China. Improving crop water use efficiency can increase crop production levels and the efficient use of water resources under climate change conditions. This study investigated the effects of climate change on crop water use efficiency in the northwest semiarid region by statistically analyzing crop yields, soil moisture, rainfall and temperature data over the past 50 years. The results showed that, compared with 1960–1969, a temperature rise of 1.6 °C and an annual rainfall reduction of 105.6 mm occurred between 1990 and 2009 and the water use efficiency of wheat, potatoes and corn increased by 10.7, 4.5 and 12.2 kg hm−2 mm−1, respectively. Due to climate warming and to a fall in rainfall over the past 50 years, water use efficiency by wheat (Triticum aestivum), potatoes (Solanum tuberosum) and corn (Zea mays) have significantly increased, which shows that climatic change can improve water use efficiency.