毛乌素沙漠与黄土高原过渡带气候变化对玉米产量的影响

EFFECT OF CLIMATE CHANGE ON CORN YIELD IN YULIN,NORTH SHAANXI PROVINCE OF CHINA

基于1971～2012年榆林市气象数据和玉米产量数据,分析过去42年毛乌素沙漠与黄土高原过渡带玉米生长期内气候因子的变化趋势,并利用一阶差分法、相关分析、多元逐步回归法分析各生育阶段气候因子对玉米产量的影响.研究结果表明:过去42年,玉米生长期内热量资源呈显著增加的趋势,生长期平均温度、平均最高温度和平均最低温度分别增加0.24℃/10 a、0.26℃/10 a和0.32℃/10 a,降水量、光照时数无显著变化.一阶差分、回归分析结果表明,玉米产量与全生长期平均温度、平均最高温度、积温呈极显著的负相关,其中与平均温度相关系数最大,全生长期温度每升高1℃,玉米减产835.5kg/hm2;与降水量变化呈显著正相关,降水量每增加100mm,玉米增产364.7kg/hm2;与日照时数变化呈负相关,日照时数每增加100h,玉米减产325.8kg/hm2.各生育阶段中,出苗-三叶期至灌浆乳熟期的平均最高温度、平均温度及苗期日照对玉米产量产生负影响,七叶-拔节期的降水和成熟期的平均最高温度对玉米产量产生正影响;多元逐步回归模型分析结果表明,显著影响玉米产量的是抽雄-开花期和灌浆-乳熟期平均最高温度、拔节期降水量、出苗-三叶期日照,模型能够解释毛乌素沙漠与黄土高原过渡带玉米56％的产量变化.

The study analyzed the effects of climate change on corn yield in Yulin,the typical ecotone between Mu Us desert and Loess Plateau in north Shaanxi province of China,based on the meteorological data and statistics data from 1971 to 2012.The methods of first order difference,correlation analysis and multiple liner regression were used.The results showed that the heat resource for whole corn growth period increased significantly during the past 42a.The average temperature,average maximum temperature and mean minimum temperature increased by 0.24℃/10a,0.26℃/10a and 0.32℃/10a,respectively.The changes of precipitation and sunlight hours were not as obvious as the temperature during the corn growth period.The average temperature,average maximum temperature,accumulated temperature had significant negative correlation with maize yield.The correlation coefficient between maize yield and the average temperature was the biggest.Whenthe average temperature increased by 1 ℃,maize yield would decrease by 835.5 kg/hm2;However,the precipitation increased by 100mm,maize yield would increase by 364.7kg/hm2;and when the sunlight hours increased by 100h,maize yield would decrease by 325.8kg/hm2.For the each growth stage,the average maximum temperature,average temperature from three leaves stage to milking stage,and the sunlight hours at seedling stage had negative influence on the yield of maize.The precipitation at the seven leaves-jointing stage and the average maximum temperature at the maturity showed positive effect on maize yield.The average maximum temperature during pumping male flowering and maturity stage,the precipitation of jointing stage,and the sunlight hours during the seedling-three leaves stage had significant influence on the maize yield.The model can explain the 56％ change of maize yield in the typical ecotone between Mu Us desert and Loess Plateau.