Study On Adaptability Adjustment Simulation Of Rice Production In Southern Henan In Future Climate Change

Agriculture plays an important role in the development of national economy.While climate change is the most direct environmental factor affecting agriculture.In recent years,an increase in average temperature,abnormal climate and extreme weather events occur frequently,which has caused increasingly serious effects on national agricultural production.Facing the future climate change,existing farming practices may not meet the needs of future agricultural production.Thus,producers would have to adopt to it.So in the assessment study of future climate change,adaptability adjustments,such as optimizing rice varieties,changing the sowing time and so on,are taken into account,which are more conforming to actual production.Southern Henan is the main rice-producing region in the whole Henan province.The research on rice in southern Henan Province is the vital significance.Moreover,Xinyang is the largest rice-producing areas in Southern Henan(89%).Therefore,to illustrate the climate change on the influence of rice production in Xinyang can get close to that in Southern Henan.So this study has chosen Xinyang area as a research area,and selects 3 representative varieties:the early,middle and late-maturing as the object of study.Then researches are conducted on adaptability adjustment of climate change.According to Special Report on Emission Scenarios(SRES)of the Intergovernmental Panel on Climate Change(IPCC)in the A2 and B2 scenarios,combined with Regional Climate Models(PRECIS)done by Climate Prediction and Research Centre of Hadley in the United Kingdom,9 benchmarks(1961-1990)and future(2021-2050)daily meteorological data are generated.Selecting the latest version ORYZA-V3 jointly developed by the Wageningen University of the Netherlands and the International Rice Research Institute in the Philippines,and considering future direct gain under the effects of CO2,two conditions are divided:rain-fed and irrigation.They are used respectively for simulation and analysis of the future impacts of climate change on rice production.On this basis,adaptability adjustment of rice production is simulated and analyzed in different future scenarios.Finally come to the conclusion of the production,the stability and changes in the total output of rice in Southern Henan after that.The main results are as follows:(1)The temperature of 9 sample sites in the next 30 years tends to increase.Total temperature during rice growth period is 1.6-1.9?.The mean temperature increases by 1.8? and 1.7? respectively in A2 and B2 scenario.Each sample point during rice growth period increases by 1.8-1.9? in the A2 scenario,and 1.6-1.8? in the B2 scenario.Total radiation during rice growth period in the future is increasing,but the increase tends to slow down.All sites are 10%on average.The growths are similar in two future scenarios,and it is also close among each point.Judging from the radiation fluctuations of the next 30 years,fluctuations of rice growing period in the A2 scenario will be larger than that in the B2 scenario.In future climate change,precipitation of all sites during rice growth period in Xinyang shows a growing trend by 20%-30%.In the same scenario,precipitation change has no difference between all points.Precipitation in the A2 scenario increases slightly larger than that in the B2 scenario.(2)In the A2,B2 scenarios,the rice growth period of all sample sites relative to the BASE period will be shorted by ranging from 3 to 5 days.The period will be shorted by 4.7 days and 4.5 days under both rain-fed and irrigated conditions in A2 scenario.Meanwhile it is shorted most in Xixian,Xinyang,Huaibin,which is up to 5 days.While it is 3.2 days respectively under rain-fed and irrigation conditions in B2 scenario.The growth period may be shorted by 4 days in Xixian and Xinyang,which is considerably relative to future warming.(3)In the future climate change,if adaptability adjustments and the direct gain effect of CO2 are not taken into account of,the simulation yield in the A2 scenario in Xinyang Prefecture is 14.1%less than that in BASE period,and decreases by 8.6%in B2 scenario.Whether considering rain-fed and irrigation conditions or not,the stability in the A2 scenario is worse than that of B2 scenario from the stability of rice production in the future.While irrigation measures can significantly improve the stability of rice production.(4)Through the adaptability adjustments simulation,such as varieties and sowing time,meanwhile fertilizer effects of CO2 are taken into account of,yield increased by 17.2%and 15.7%,respectively in A2 and B2 scenarios in Xinyang area.Total yield in the A2 and B2 scenarios increased by 14.8%and 13.2%,which is more than that in BASE period.Therefore,assessment on future climate change including adaptability adjustment of crop production,is not only more reasonable but also more optimistic.