为了探索降水与温度变化对旱地春小麦产量的影响,本研究以定西市安定区1971—2012年共42年的逐日气象数据为基础,运用APSIM(agricultural production system simulation)模型对不同降水(逐日降水±20％、± 15％、±10％、±5％、±0％)与温度(逐日温度±2℃、±1.5℃、±1℃、±0.5℃、±0℃)变化下的旱地春小麦产量进行了模拟,并采用二次多项式回归、单因素边际效应和通径分析研究了温度和降水变化对春小麦产量的影响机制.结果表明:在试验设计范围内,春小麦产量(Y)与降水(X1)和温度(X2)变化编码值的回归方程为Y＝1452.24+2693.88 X1-287.25X2-200.38X22-344.47X1X2(R2＝0.999,P<0.01).当温度不变时,降水与春小麦产量呈正线性关系,由模拟结果可知,降水每增加5％,春小麦产量最大增幅为21.38％,平均增幅为14.31％;当降水不变时,温度与春小麦产量呈开口向下的二次函数递减关系.根据模拟结果,温度每升高0.5℃,春小麦产量最大降幅为4.92％,平均降幅为3.24％;通径分析显示,温度和降水之间存在负互作效应,但降水增加对春小麦产量的增产效应远大于温度升高所造成的减产效应.%Climate change has a great impact on agricultural production,temperature and precipitation change are one of the most important factors.In the arid and semi-arid areas,this effect is even greater.Spring wheat is one of the most important food crops in this area.In order to explore the effects of change of precipitation and tempera-ture on spring wheat yield in drylands.In this paper,based on the daily meteorological data of a total of 42 years from 1971 to 2012 in Anding District of Dingxi city,the simulation of spring wheat yield in different precipitation(Daily precipitation ±20％,±15％,±10％,±5％,±0％)and temperature(Daily temperature ±2℃,±1.5℃,±1℃,±0.5℃,±0℃)conditions using agricultural production system simulation model(APSIM),studied the in-fluence of temperature and precipitation on spring wheat yield mechanism by adopting two polynomial regression,path analysis and marginal effect of single factor.The results showed that the yield of spring wheat(Y)and change encoding values of precipitation(X1)and temperature(X2)regression equation for Y＝1452.24+2693.88X1-287.25X2-200.38X22-344.47X1X2(R2＝0.999,P<0.01)within the scope of the design of the experiment.when the temperature is constant,precipitation and yield of spring wheat were positively linear relationship,the simula-tion results showed that the precipitation increased 5％each,yield of spring wheat biggest increase was 21.38％,the average growth of 14.31％; When precipitation unchanging,temperature and yield of spring wheat quadratic function decreasing relationship was open to the bottom,each elevated temperature of 0.5℃,the spring wheat yield biggest drop was 4.92％,the average decline of 3.24％.Path analysis showed that the existence of a negative inter-action between temperature and precipitation effect,but the increased precipitation effect on the increase of spring wheat yield is greater than the temperature rise.
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