Response Of Early Rice Phenological Period And Yield To Climate Change In JiangXi Province

Global warming has brought great influence to agricultural production.As one of the three major food crops in China,rice has an important and far-reaching significance in correctly assessing the impact of climate change.Therefore,this study takes the early rice“GanXin203”as the research object,and uses the sub-model CERES-Rice in the modified DSSAT4.6 model to simulate the phenological period and yield of the early rice“GanXin203”in Jiangxi Province from 1961 to 2016.The characteristics of climate resources in the early rice growing season,the impact of climate change on early rice production,and the key climate factors affecting early rice production.The main findings are as follows:1)The DSSAT model was used to participate in the verification;the genetic parameters of the early rice“GanXin203”were obtained by using the GLUE module in the model;the verification results showed that the RRMSE of the simulated and measured values of flowering,maturity and yield were 2.75%、1.78%and 8.79%;DSSAT model has good applicability to early rice production in Jiangxi Province.2)From 1961 to 2016,the first day of≥10℃in Jiangxi Province showed an early trend.The southern part of Jiangxi Province was 11 days earlier than that of northern Jiangxi,and it was 10 days earlier than that of the middle of the Jiangxi.The average temperature and the highest daily temperature of≥35℃in the early rice growing season(April-July)were The rising(increasing)trend,rainfall and sunshine hours showed a downward trend,the propensity rates were 0.162℃/10a、0.78d/10a、-11.048mm/10a、-15.562h/10a;the average temperature spatial distribution from low latitude At high latitudes,the high-value areas with the highest temperature of≥35℃are mainly distributed in the northeastern part of Jiangxi and the middle of the Jiangxi,The spatial distribution of rainfall and sunshine hours increases from southwest to northeast.3)The simulation results showed that there were some advances in the early flowering stage of the Jiangxi Province,the advance days were 1.93d/10a、0.8d/10a、and 0.9d/10a respectively.The early rice matured in the northern Jiangxi and central Jiangxi has advanced,the number of days ahead is 1.7d/10a、1.4d/10a,delayed in southern Province,and the number of days delayed is 0.7d/10a;the average number of days in early rice growth in the province is 128d;the yield of early rice in the north of Jiangxi is on the rise,middle and south showed a downward trend,the propensity rates were 214.3kg/hm~2、-89.1kg/hm~2、-100.7kg/hm~2,respectively;the average annual yields of the early rice in north,middle and south were 7252.8kg/hm~2,5947.6kg/hm~2,6319.1kg/hm~2.4)Analysis of the correlation between climatic factors and meteorological yields shows that when the average temperature rises by 1°C,the early rice yield is reduced by150.6kg/hm~2,the highest temperature is increased by 1°C,the early rice is reduced by283.6kg/hm~2,the rainfall is increased by 100mm,and the early rice is increased by12.7kg/hm~2,the sunshine hours increased by 100h,and the early rice yield decreased by134.1kg/hm~2.The analysis indicated that the key climatic factors affecting early rice yield were temperature and sunshine hours;and the early rice yield in middle was significantly more sensitive to climate change than that of north.and south;and southern JiangXi has the best climate stability.The adverse effects of climate change on early rice are mainly reflected in the increase in meteorological disasters and biological disasters affecting their yield stability.Therefore,climate change adaptive cultivation technology is the most reasonable and effective way to increase production;it mainly includes two aspects.First,disaster prevention and avoidance technology:focus on the characteristics and laws of natural disasters and biological disasters such as low temperature,high temperature and drought.And the corresponding cultivation techniques;the second is the early rice planting pattern and adjustment to adapt to climate change:such as the selection of new varieties,adjustment of sowing date and farming system,and the maturity of varieties,to make full use of climate resources to improve early rice yield.