Estimation of the Impact of Climate Warming on Spring Wheat (<i>Triticum aestivum</i> L.) Phenology From Observations and Modelling in the Arid Region of Northwest China

ABSTRACT Climate warming has induced shifts in the phenological period and thus affected cultivar selection and effective crop management. Particularly, the great climate warming in the dry environment could have more effects on the phenology of spring wheat with the distinct cycle of biological events during growth. In this study, the daily observations of spring wheat phenology and meteorology from 1991 to 2018 were used to analyse changes in phenology concerning accumulated temperature in the Hexi Corridor region of Northwest China. Five crop growth models (WheatGrow, WOFOST, CropSyst, CERES‐Wheat and APSIM‐Wheat) were selected to evaluate the reliability of the phenological stage simulations in the study region. Results show that in the past 28 years, the annual accumulated temperature in the whole growth period from sowing to maturity increased by 3.08°C–8.35°C/a at three sites of the region. Climate warming shortened the phenological period at rates of 3.56–4.49 days/10a, mostly attributed to the shortened duration from anthesis to maturity. Statistical analysis demonstrated that the shortened phenological period cannot be simply expressed by the linear correlation between the length of phenological phases and accumulated temperature in the respective growth stages. The five wheat growth models after parameter validation can generally capture the phenological dates, and WOFOST performed best at the three sites. However, when the calibrated model was used for simulations of long‐term variations of phenological dates, the accumulated errors in simulations could result in large deviations of the predicted physiological change to the observations.