Abstract:

On the basis of ecological physiology characteristics of winter wheat and mathematical statistics method, the suitability function was constructed about temperature, precipitation and sunshine, respectively by using the 1960-2016 meteorological data from 37 stations in Huaibei Plain of Anhui province. In order to express the synergetic effect of meteorological factors and yields, winter wheat climate suitability modeling across the whole growth stage was established by combining the above single factor suitability function. On the other hand, agricultural climate annual assessment model was also established based on crop climatic suitability index. Results indicated that the suitability indexes in each growth stage of winter wheat were different. All single factor climatic suitability indexes were higher in the filling-milk stage, yet lower during the reviving-jointing stage. The lowest precipitation suitability appeared at the tillering stage. The temperature suitability of winter wheat in Huaibei plain of Anhui province kept higher level, following the sunshine, and precipitation became less suitable. Heat resource was abundant, and precipitation was the main limiting factor for the growth. The climatic suitability at the tillering stage was not only low, but also the variation coefficient was large, which indicated that Huaibei Plain was prone to autumn-winter successive drought, with the fluctuation of winter wheat yield. The distribution of winter wheat climate suitability in eastern areas was higher than that in northern areas, and planting risk were relatively high in western Huaibei and area along Huaihe River. The temperature suitability in the whole growth stage of winter wheat showed an significant increasing trend during 1961-2016, and the suitability index of precipitation showed a similar trend but not significantly, while the suitability index of sunshine showed an obvious downward trend. Due to the interaction between the three factors of temperature, precipitation and sunshine, the climate suitability index had not an obvious linear trend on the whole. From the spatial change of view, it increased slightly in the eastern Huaibei, while decreased slightly in the west and areas along the Huaihe River. From the view of probability density distribution, Huaibei Plain was in the middle of climate suitability level for most of the years, and the occurrence probability of the lower climatic suitability was greater than that of the higher one. In addition, winter wheat climate annual assessment was carried out based on the climate suitability classification, and the evaluation results and real grade of climate yield abundance were coincident. The accuracy of the assessment model can basically meet the needs of agro-meteorological operation and services.

Key words: climate suitability, agricultural climate annual assessment, winter wheat, Huaibei Plain of Anhui province