Variation Characteristics Of Climatic Resources And Production Potential Of Maize In Sichuan

In the context of global warming in recent years,the light,heat,and water resources required for maize growth and development have changed accordingly,which in turn affects the yield of maize.Based on the daily meteorological data of 21 meteorological observation stations in the corn producing area of Sichuan Province from 1981 to 2019,the yield potential,harvest index and growth period length of corn were simulated by Hybrid Maize model.Combined with Arc GIS Kriging interpolation analysis method,the temporal and spatial variation characteristics of light,temperature,water,drought,yield potential,harvest index and growth period length of maize in the maize producing area of Sichuan Province were analyzed,and the correlation coefficients between meteorological factors and yield potential were calculated,and the cultivation and management measures to adapt to climate change were analyzed so as to provide a scientific basis for further exploiting the yield potential of maize.The main results of this study were as followed:1.In terms of heat resources,there is an overall warming trend in temperature,especially during the"sowing-pulling"period,and the transition points were occurred in the 1990s.In terms of spatial distribution,the temperature gradually increased from northeastern to southwestern Sichuan during the nutritional growth period of maize,while gradually decreased from northeastern to southwestern during reproductive growth period.In terms of light resources,the cumulative sunshine hours and the cumulative solar radiation generally showed a fluctuating downward trend,with the highest cumulative sunshine hours and the cumulative solar radiation during the"seeding-pulling"period of maize.In terms of spatial distribution,the cumulative sunshine hours and the cumulative solar radiation in northeast and southwest Sichuan were higher than those in central Sichuan.In terms of precipitation resources,the cumulative rainfall showed a fluctuating downward trend,with the transition point occurred in 1993.In terms of spatial distribution,rainfall showed a pattern of decreasing from northeastern Sichuan to southwestern Sichuan except for the"sowing-pulling"period,and the rainfall in northeastern and southwestern Sichuan was generally greater than that in central Sichuan during the whole reproductive period and the other three reproductive stages.2.In terms of drought characteristics,the frequency of drought in the whole growth period of maize in Sichuan province was distributed between 0 and 46%from 1981 to2019,and drought occurred most frequently in the eastern and western parts of the Sichuan basin,with the ratio of drought stations increased year by year,and the scope of drought expanded year by year.The drought frequency and drought station ratio in the nutritional growth stage of maize were greater than those in the reproductive growth stage,especially in the"sowing-pulling"stage,where the drought frequency and drought station ratio were the highest.In the nutritional growth stage of maize,drought occurred more frequently in southwest Sichuan than in northeast Sichuan,and in the reproductive growth stage of maize,drought occurred more frequently in northeast Sichuan than in southwest Sichuan.3.In terms of maize production potential,the average of maize photo-thermal potential productivity in Sichuan Province was distributed between 8000-10000 kg/hm~2and the average of maize climate potential productivity was distributed between 5100-9500 kg/hm~2from 1981 to 2019.Both maize photo-thermal potential productivity and maize climate potential productivity showed a decreasing trend year by year,the photo-thermal potential productivity of maize in Sichuan Province decreased by 183 kg/hm~2per decade,and climate potential productivity of maize decreased by 332 kg/hm~2per decade.The decreasing trend of maize photo-thermal potential productivity was more obvious in northeastern Sichuan and some regions of southwestern Sichuan,and the decreasing trend of maize climate potential productivity was more obvious in northern Sichuan Basin and some regions of southern Sichuan.The photo-thermal potential productivity of maize generally showed a trend of gradual increase from northeast Sichuan to southwest Sichuan,and the climate potential productivity of maize showed a pattern of higher in southwest Sichuan and the eastern parts of the Sichuan basin than in central Sichuan.4.In terms of Correlation between meteorological factors and production potential,The limiting factor that restricted the photo-thermal potential productivity of maize was temperature in Sichuan;the limiting factor that restricting the climate potential productivity of of maize was precipitation in Sichuan,and the secondary factor was temperature,especially in the"jointing-tasseling"and"tasseling-milking"periods of maize,the influence of rainfall on maize climate productivity was more significant.5.In southwest Sichuan,the temperature was higher,sunshine and rainfall were sufficient during the growth stage of maize,and photo-thermal potential productivity of maize and the climate potential productivity of maize were generally higher.In central Sichuan,the temperature was suitable in the growth stage of maize,but the sunshine and rainfall were insufficient,and the climate potential productivity of maize was low.In northeast Sichuan,the temperature was lower in the growth stage of maize,sunshine and rainfall were sufficient,and photo-thermal potential productivity of maize was lower.