| Based on the daily meteorological data from 1994 to 2023 and the growth period data of drought-saline wheat from agrometeorological experimental stations in the main coastal drought-saline wheat planting areas of Cangzhou, Hebei Province, this study systematically analyzed the variation characteristics of precipitation, sunshine, and thermal resources during the whole growth period and key growth stages of drought-saline wheat, and identified the key meteorological factors affecting its yield by using methods including linear trend estimation, Mann-Kendall (MK) trend test and mutation test, and Pearson correlation analysis. The results showed that: (1) The precipitation during the whole growth period of coastal drought-saline wheat in Cangzhou, Hebei Province showed an increasing trend. Combined with the pre-sowing precipitation and summer precipitation in the sowing year, natural precipitation could meet the water demand of drought-saline wheat in 100% of the years. However, the precipitation varied significantly among different years and growth stages: the proportions of years where precipitation met the demand were 76.7%, 66.7%, 1.4%, and 26.7% for the sowing-overwintering stage, overwintering-regreening stage, regreening-heading stage, and heading-maturity stage, respectively. (2) The sunshine duration during the whole growth period and grain-filling stage of the wheat showed an increasing trend. A significant mutation in the sunshine duration during the grain-filling stage occurred around 2009, with a notable increase. The annual average sunshine duration during the grain-filling stage was 9.1 h·d?1, indicating sufficient sunlight. (3) The accumulated temperature above 0℃ during the growth season of the wheat showed an extremely significant increasing trend (P < 0.01), with 76.7% of the years having an accumulated temperature exceeding 2000℃; 50% of the years had a negative accumulated temperature (below 0℃) within -200℃. However, the minimum winter temperature showed a significant decreasing trend (P < 0.05), with 43.3% of the years having a minimum temperature below -15℃. The diurnal temperature range during the grain-filling stage was between 11.5–13.5℃ in 90% of the years, with a significant decrease during 2010–2016. The number of days with a daily maximum temperature above 32℃ during the grain-filling stage showed a significant increasing trend (P < 0.05), while the number of days with a daily maximum temperature above 35℃ showed a decreasing trend. (4) The annual yield of coastal drought-saline wheat in Cangzhou, Hebei Province was significantly positively correlated (P < 0.05) with the precipitation during the whole growth period, summer precipitation in the sowing year, pre-sowing precipitation, precipitation during the regreening-heading stage, and sunshine duration during the whole growth period and grain-filling stage; all these factors showed an increasing trend over the 30 years. Water is the main limiting factor for coastal drought-saline wheat in Cangzhou, Hebei Province. It is necessary to improve water use efficiency through precision irrigation and rainwater harvesting technologies, and match cold-resistant, drought-tolerant, and early-maturing varieties to reduce climate risks. The results of this study provide a theoretical basis for the rational development and utilization of climatic resources in drought-saline wheat planting areas, variety improvement, and field management. |
基本信息
