Estimating future climate change impacts on wheat yield and water demand in Xinjiang, Northwest China using the DSSAT-CERES-Wheat model
Xuehui Gao, Jian Liu, Yue Wen, Haixia Lin, Yonghui Liang, Mengjie Liu, Zhenpeng Zhou, Jinzhu Zhang, Zhenhua Wang
Abstract
• Climate change is expected to increase wheat grain yield, biomass, and ET c in Xinjiang, Northwest China. • Six GCMs projected an overall increase in growing season temperature and precipitation. • Climate change shortens winter wheat growth period, advancing anthesis and maturity by 1–34 days. • Future irrigation water demand decreases 18.99–27.76% under climate change. Climate change is challenging to maintain and increase crop production in environmentally sensitive regions. The assessment of climate change’s impact on Chinese wheat production is needed for irrigated farming to maintain wheat self-sufficiency and assure future food demand. We assessed future trends in wheat yield, biomass, and crop evapotranspiration (ET c ) in arid northwest China using the calibrated DSSAT-CERES-Wheat model and daily climate data based on projections made by six global climate models under two representative concentration pathways (SSP245 and SSP585) of greenhouse gas emissions. Forecasts indicated a gradual increase in both temperature and precipitation for the region, depicting a discernible shift towards a warmer and wetter climate. Subsequent findings suggested that, in comparison with the baseline period (1991–2020), climate change was anticipated to shorten the winter wheat growing season. The anthesis date was expected to come earlier by an average of 1–20 days under SSP245 and 2–34 days under SSP585. Similarly, the date of physiological maturity under SSP245 and SSP585 was expected to come earlier by an average of 1–13 days and 2–23 days, respectively. Irrigated winter wheat grain yield and aboveground biomass were projected to increase over time, with increases ranging from 12 % to 32 % and from 14 % to 25 %, respectively. The modeling results further suggested that the optimum irrigation amount for the study area would be 329 mm during the baseline period, and that irrigation demand in the future could be reduced by 18.9–27.7 % compared with the baseline period. Our findings will help policymakers and agricultural stakeholders adapt to climate change, ensuring optimal wheat production from this region’s irrigated cropping systems.