The Simulation Analysis Of Spring Wheat Yield Forming To Response Of Climate Change

The impact of climate change on agricultural production can not be ignored,the Loess Plateau region as a typical rainfed agricultural areas,are more sensitive to climate change.The aim of this study was to study the response of spring wheat yield and its constituent factors to climate change.The APSIM model was used to simulate the yield and its constituent factors.Then,the meteorological data of Anding District in Dingxi City from 1971 to 2016 were combined.Finally,the relationship between climate cha nge and spring wheat yield and its climatic potential was studied.The main conclusions are as follows:1.By comparing the simulation value and measured value of yield,ear number,grain number per spike,1000 grain weight and biomass of the upper part of spring wheat,The results show that the decision coefficient R2 is greater than 0.8,and the model validity parameter ME is greater than0.7,it shows that APSIM model can simulate spring wheat yield and its formation process more accurately.2.The solar radiation and temperature in the study area are on the rise,the precipitation is downward,and both of them have obvious volatility.The changes of meteorological factors in the whole year and spring wheat growth period are as follows: solar radiation tendency rates were20.21MJ/(m~2·10a)and 8.11MJ/(m~2·10a);precipitation tendency rate respectively-5.64mm/10 a and-1.30mm/10a;mean temperature tendency rate were 0.60 ? /10 a and 0.62 ?/10a;minimum temperature tendency rate were 0.71?/10 a and 0.79?/10 a,whole growth period of spring wheat growth is slightly bigger than the year;the maximum temperature tendency rate were 0.50?/10 a and 0.51 ? /10a;overall,the mean temperature of growth were greater than the minimum temperature,less than the maximum temperature.3.The increase of solar radiation and air temperature in the study area is disadvantageous to the increase of spring wheat yield,and the increase of precipitation is beneficial to the yield increase.In spring wheat growth period,solar radiation and yield are extremely significant negative correlation(-0.434**),precipitation and yield are extremely significant positive correlation(0.561**),the maximum temperature and yield are significantly negatively correlated(-0.304*),the mean temperature(-0.196)and minimum temperature(-0.071)are negatively correlated with yield,thecorrelation between precipitation and yield is the highest.In the different growth periods of spring wheat,solar radiation was negatively correlated with yield in all growth period;precipitation and yield at sowing period(-0.186),tillering period(-0.021)and flowering period(-0.050)are negative correlation,in other period are positive correlation;the mean temperature and yield in the seedling period has a weak positive correlation(0.009),in other period are negative correlation;minimum temperature and yield at seedling period(0.005)and tillering period(0.081)are negative correlation,in other period are negative correlation;The maximum temperature and yield are negative correlation in all growth period;the correlation between the ratio of precipitation to mean temperature and yield is similar to that of yield and precipitation;the correlation between the difference between maximum temperature and minimum and yield is similar to that of yield and maximum temperature.4.In the whole growth period of spring wheat,the increase of solar radiation,the average and maximum temperature are not conducive to the increased spike number and grain weight,but increased the grain number;the increase of rainfall is conducive to the increase of panicle number and grain weight increased,but not conducive to panicle;the lowest temperature is conducive to the increase of grain weight,but not conducive to the increase of spike number and grains per spike,this reflects the mutual restriction and mutual compensation between the three elements of production.In the different growth periods of spring wheat,the minimum temperature in sowing period is significantly negative correlation with ears(-0.436**),but the minimum temperature in seedling period is significantly positive correlation with ears(0.504**);the minimum temperature in booting period(0.305*)and flowering period(0.435**)are very significantly positive correlation with grains number;the maximum temperature in grain filling period(0.351*)is significantly positive correlation with 1000 grains weight.5.The photosynthetic productive potential of spring wheat in the study area is the overall upward trend,the average growth rate of 54.76kg/(hm~2·10a),the upward trend is cyclical,and the cycle in accordance with the change of solar radiation;the trend of the light warm production potential is also rising,and the growth rate [457.79kg/(hm~2·10a)] is greater than the photosynthetic productive potential;the trend of climate productive potential is also rising,but the growth rate[260.20kg/(hm~2·10a)] is lower than the light warm production potential,and interannual variability is large.Climate production potential is very significant positive correlation with precipitation in spring wheat growth period,and is significant positive correlation with minimumtemperature in the period.