关键词: 冬小麦, 灌溉制度, 补偿效应, CERES-Wheat模型, 黄淮海平原

Abstract: Huang-Huai-Hai Plain (3H Plain) is widely accepted to be the largest winter wheat growing areas of China. Water shortage is comprehensively recognized as the limiting factor for winter wheat growth. In the context of global warming, precipitation and evapotranspiration during wheat growing period have experienced significant changes. Consequently, understanding the impact of different irrigation strategy on wheat yield is essential for establishing climate adaptation strategies in 3H Plain. In this paper, the phenology and yield data of six typical agro-meteorological stations representing six sub-regions were used to calibrate the CERES-Wheat crop model. Based on the calibrated model and the future climate projected by HadGEM2-ES under RCP8.5 scenario, the yield reduction rate under rain-fed conditions compared to potential yield for the short-term (2010-2039), medium-term (2040-2069) and long-term (2070-2099) were analyzed. Then the yield retrieval ability of different irrigation strategy was compared. Results showed that, compared to full-irrigated yield, rain-fed condition would decline wheat yield by 47.3%, 53.5% and 50.9% for the short-term, medium-term and long-term respectively, with the spatial distribution of higher reduction rate in sub-region Ⅰ to Ⅳ (north), and the reduction rate in sub-region Ⅵ(south) only 7.4% (short-term) ,12.8% (medium-term) and 9.7% (long-term). Comparison of different irrigation system showed there is a big difference in compensation effect (i.e. the difference of the reduction rate under rain-fed and irrigation condition) of winter wheat on different growth stage. And the compensation effect of northern sub-region was higher than that of Southern sub-region. The efficiency of irrigation on jointing stage was the highest, of which the yield retrieval ability was 16.3-18.6 percent point for different future period. The second was irrigation on grain filling stage, of which the yield retrieval ability was 5.1-6.1 percent point. While irrigation on overwintering stage could only retrieve yield by 0.4-0.6 percent point. Further analysis showed that irrigate on both jointing stage and grain filling stage could retrieve yield by 23.6-25.1 percent point. Thus, under the recognition of higher risk of water shortage in the future, securing irrigation supply for jointing stage is of first priority. And if two-times irrigation was allowed, irrigate on both jointing stage and grain filling stage could retrieve half of the yield losses.

Key words: Winter wheat, Irrigation system, Compensation effect, CERES-Wheat, Huang-Huai-Hai Plain