Abstract:

To investigate the patterns of phenological stage evolution and their driving mechanisms for winter wheat in Hengshui City, this study utilized observational data from agricultural meteorological stations in the region from 1990 to 2020 to establish a comprehensive database covering the entire growth and development process of winter wheat and corresponding meteorological elements. Using a combination of Pearson correlation analysis and multiple regression models, we conducted a quantitative study of the temporal variations in winter wheat phenological stages over the past 30 years and systematically analyzed the trends in major climatic elements during the growing season (October-June of the following year), ultimately clarifying the intrinsic relationship between phenological dynamics and meteorological factors. The analysis results showed that between 1990 and 2020, the average air temperature and average soil temperature throughout the entire growth period of winter wheat in Hengshui City generally exhibited a fluctuating upward trend. Among these, the upward trends in May air temperature and March soil temperature were the most pronounced, with increases of 0.81℃/10 years (P<0.001) and 1.54℃/10 years (P<0.01), respectively, while the number of hours of sunshine showed a downward trend. The pre-winter growth period of winter wheat consistently exhibited a trend of delay, while the post-winter growth period consistently showed a trend of advancement, resulting in an overall shortening of the growth cycle at a rate of approximately 3.46 days per 10 years. From the perspective of growth stages, there was a significant negative relationship between the growth-day index and sunshine duration during the pre-winter stages, whereas the growth-day index during the post-winter stages showed a clear negative correlation with both air temperature and soil temperature. Among meteorological factors, air temperature has the most significant impact on changes in the growth period, exerting a pronounced negative regulatory effect on the number of growth days. The growth cycle of winter wheat in Hengshui City exhibits a distinct asymmetric pattern characterized by “delayed pre-winter growth and shortened post-winter growth.” The fundamental driving force behind this is the strategy of shortening the growth period to avoid the harmful effects of high temperatures; however, this may also result in reduced tillering and insufficient grain filling due to insufficient time for the accumulation of photosynthetic products.

Key words: winter wheat, meteorological factors, growth stage, air temperature, climate change