基于WMAIP集成模型的华北冬小麦适宜播期与冬前积温下限研究OA北大核心CSTPCD

Global warming has direct impacts on agricultural production and food security.The North China Plain(NCP)has adopted the double later-cropping system(the later sowing of winter wheat and the later harvest of summer maize)as a strategy to cope with climate change and increase yield.Determining the latest sowing period for winter wheat in this region under the backdrop of climate change is crucial for ensuring high yield and efficiency,thereby safeguarding China's food security.Based on the WMAIP integrated model,the suitable sowing period and the minimum pre-winter accumulated temperature were analyzed for winter wheat at six representative sites in NCP,including Beijing and Tianjin in the north,Xingtai and Ji'nan in the middle,and Xihua and Nanyang in the south.The results showed that the yield reduction rate due to late sowing was increased from south to north in NCP,with the southernmost part of NCP having the smallest reduction rate(＜19.5％),the central part having a reduction rate within 26.4％,and the northernmost part having the largest reduction rate,reaching up to 32.0％.The suitable sowing periods for the northern,central,and southern parts of NCP were between September 25 and October 5,September 30 and October 20,and October 10 and November 5,respectively.All sites showed a very significant quadratic relationship between the high stability coefficient and the pre-winter accumulated temperature.Based on this quadratic relationship,the lower limit of suitable pre-winter accumulated temperature can be determined.The suitable pre-winter accumulated temperature for winter wheat varied at different sites,showing a gradually decreasing trend from north to south in NCP.The suitable pre-winter accumulated temperature limits for winter wheat in NCP,based on high yield and high water use efficiency,were between 497℃·d and 629℃·d and 344℃·d and 581℃·d,increasing from south to north.Under conditions of high yield,the latest sowing dates for the majority of regions in Hebei,Shandong,and Henan were between October 1 and October 13,October 10 and October 16,October 22 and October 28,respectively,and under high water use efficiency conditions,they were extended to October 7 and October 19,October 16 and October 22,and October 31 and November 12.The insights can provide a reference for the promotion and application of the double later-cropping system in NCP under the context of global warming.