Study On Climate Change Adaptation Of Winter Wheat In China Under RCP8.5 Scenario

Wheat is one of the three major grain crops in China.Its sown area accounts for about 20% of the national crop sown area and 20% to 25% of the grain output.Overuse of water and fertilizer resources reduced the sustainability of agricultural production and causes serious environmental hazards.Under the background of global warming,reducing the input of water and fertilizer in agriculture and increasing regional crop yield will be an important research direction in the field of agriculture in China.This paper analyzed the changes of different climatic factors during the growth period of winter wheat under RCP 8.5 scenario,and simulated the adaptability of different water and fertilizer interaction treatments to climate change under RCP 8.5 scenario using DSSAT-CRESS-Wheat model.The main results are as follows:(1)Under the RCP8.5 scenario,the maximum temperature during the growth period of winter wheat was increasing compared with the baseline period.The recent temperature increase range was 0~2°C,and the medium-term temperature increase range was 2.7~4.5°C.Compared with the baseline period,the lowest temperature during the growth period of winter wheat showed an increasing trend.The recent temperature increase ranged from 0 to 2 °C,and the medium-term temperature increase ranged from 3.5 to 4.5 °C.The increase in precipitation is 0% to 10%(recent)and 10% to 30%(mid-term).In recent years,the average annual radiation volume had decreased compared with the baseline period,with a decrease of less than 2%,and an increase trend in the medium term,with an increase of less than 10%.(2)The potential yield of winter wheat mainly decreases from northeast to southwest.The rainfed yield of winter wheat mainly decreased from southeast to northwest.The potential drought reduction rate in the region showed obvious north-south difference,and the potential drought yield reduction in the northern region was higher than that in the south,and gradually increased from south to north.The potential drought yield reduction in Hebei,Henan,Shanxi and Shandong was higher than the regional average.The potential yield reduction in Hebei was the largest,and the potential drought reduction in the near and medium term is 68.35% and 71.71%,respectively.The potential drought yield reductions in Hubei,Anhui,Jiangsu and Sichuan were low.(3)The yield and drought yield reduction of winter wheat under different water treatments showed a significant north-south difference.The yield of winter wheat in the south was higher than that in the north,and the yield in the north was higher than that in the south.Compared with W1,the yield of winter wheat in the lower part of W2 was higher,and then the yield increase gradually decreases from north to south;the yield decrease in the north is higher,and then the decrease in yield decreases gradually from north to south.Under W3,yield and drought reduction in the whole region remained basically stable.Under W4,the yield in the north is significantly reduced,followed by the central and western regions,and the south was basically unchanged.The drought yield reduction was similar,and the yield reduction in the north was obvious,followed by the central and western regions,and the south was basically unchanged.(4)Under different water and fertilizer treatments,the yields of other areas outside Hubei and Sichuan decreased gradually from south to north,and the yield reduction showed a trend of increasing from south to north.Under the conditions of water reduction or weight loss,the yield and yield reduction of winter wheat in Hebei and Shandong provinces were basically stable.N1W3,N2W1,N2W2,N2W3 and N3W2 are treated.The yield and yield reduction of Henan,Gansu,Shaanxi and Shanxi provinces were basically stable.The processes are N1W3,N1W4,N2W1,N2W2,and N2W3.Therefore,the main producing areas of winter wheat still have higher water-saving and fertilizer-saving potential.Therefore,this study clarified the extent of climate change impacts and adaptation mechanisms for winter wheat,and provided a scientific basis for ensuring national food security.