Spatio-temporal variation in dryland wheat yield in northern Chinese areas: Relationship with precipitation, temperature and evapotranspiration

Abstract

Water supply constraints are recognized as major factors affecting regional dryland wheat production, but the details of these constraints have yet to be fully explored. We performed an analysis of field experiments conducted in northern Chinese areas during 1950-2017. Dryland wheat yields increased from the 1950s through to the 2010s at a rate of 110 kg ha-1 year-1. Yields increased most in regions with relatively high precipitation during wheat growth stage. Mean yields were 128% higher in regions with > 300 mm precipitation than in regions with < 100 mm. Yields were the highest when mean temperatures during wheat growth stage were in the range 4-8 °C. Mean yields were 1756 kg ha-1 in regions with < 200 mm evapotranspiration (ET), and 5544 kg ha-1 in regions with > 600 mm ET. Water limitation on yields decreased from the 1950s to the 2010s as precipitation during wheat growth stage increased through the regions. Yield increased significantly and linearly over time during the study period, with increasing precipitation during wheat growth stage, and with increasing ET. Overall, yield loss resulting from water deficit decreased from the 1950s through to the 2010s as precipitation during wheat growth stage increased through the drylands of northern Chinese areas.