Impact Of Climate Change On Climate Resources And Yield Of Summer Maize In Henan Province

Summer maize is the second largest food crop in Henan Province after winter wheat.Under the background of climate change,clarifying the impact of climate change on summer maize yield has theoretical significance and application value for achieving high and stable yield in Henan Province.In this paper,climate data from typical meteorological stations in Henan Province,crop data and soil data were used.The change trend of agroclimatic resources in the summer maize growing period of Henan Province from 1980 to 2018 was analyzed.Based on the DSSAT model,the potential and available yield of summer maize under the background of climate change were simulated,and the characteristics of yield differences at all levels were further analyzed.Quantitatively evaluated the response characteristics of agroclimatic resources changes and yields under different future climate scenarios,and provided a scientific basis for future development planning of summer corn production.The main results of the study are:?1?During 1980-2010,the accumulated temperature in the period of summer maize growth increased significantly,increasing by 31.4-40.6??d per 10a;the solar radiation was significantly reduced between 35.2-60.2 MJ?m^-2 per 10a and the sunshine hours decreased significantly by 24.9-42.9h/10a.The decreasing trend of rainfall was not significant,the tendency rate was between-0.88-19mm/10a.During the growing season of summer maize in Henan Province,heat resource increased,light resources decreased significantly,and inter-annual fluctuations were large.The uneven spatial and temporal distribution of precipitation increased the climate risk of maize production,which may adversely affect the stability of summer maize production.?2?The farmers'actual yield of summer maize in Henan Province increased significantly from 1980 to 2010.Advances in cultivation technology are the main reason for the increase in maize yield under the background of climate change.The potential and available yield in the five climate subregions showed a downward trend,with a decrease of 36.6-377.1 kg?ha^-1 and 59.1-583.2kg?ha^-1 per 10a.There is still a large gap between the farmers'actual yield and the potential and attainable yield,and the relative increase in yield can reach 53%.Climate change has a negative effect on summer maize yield,The average temperature is the main meteorological factor that affects the growth period and biological characteristics,followed by solar radiation,and the impact of rainfall is not significant.?3?Future climate prediction results indicate that the climate change in Henan Province shows a warm and humid trend.The degree of temperature increase is higher in the high-emission scenario than in the low-emission scenario,and the cumulative temperature increase gradually increases with time,and the overall rainfall in the future shows an upward trend,but the trend is not significant.Under the RCP4.5 scenario,the potential yield increase was higher than the RCP8.5scenario.In terms of the impact on the growth period and biological characteristics of summer maize,the days of each growth period were relatively shortened,and the degree of shortening in the mid-21st century is larger than the beginning of the 21st century,which leads to a smaller relative increase in potential production in the mid-21st century.The RCP4.5 scenario is more conducive to the growth of summer maize compared with RCP8.5.By the middle of the 21st century,the negative effect of climate change on summer maize is more obvious.