黄土高原半干旱区春小麦产量变动的影响因子分析

为揭示影响半干旱区春小麦产量波动的环境因子,依据甘肃省定西市农业气象试验站1987—2011年春小麦农业气象观测资料以及文献收集（1993—2013年）获得的春小麦耗水量与产量关系资料,分析了影响黄土高原半干旱区春小麦产量变动的环境因子。结果表明：春小麦产量与5月及主要生育期蒸发量与降水量差呈极显著的负相关关系,且负相关关系受播前土壤含水量的影响,播前土壤水分含量越大,在相同大气蒸发力条件下,春小麦产量越高,反之亦然。春小麦产量与5月份降水量以及播前土壤含水量呈正相关关系,降水量相同,播前土壤水分含量越大,产量越高,在相同土壤含水量条件下,主要生育期大气越干燥,产量越低。有效供水量可以解释60.4%的产量变率,耗水量可解释93.4%的产量变率,温度并不会对研究区春小麦产量变动造成直接影响,其通过空气饱和差影响产量形成。

Environmental Factors Influencing Spring Wheat Yield in Semi-arid Region of Loess Plateau

To investigate the effect of environmental factors on spring wheat yield in the semi-arid region, the correlation between environmental factors and spring wheat yield was analyzed based on the long-term data (1987—2011) from agrometeorological observation station in Dingxi of Gansu Province. Meanwhile, data about the correlation between water consumption and yield of spring wheat of the study area（1993—2013）were also collected from literature. The results showed that there was a significantly negative correlation between spring wheat yield and the difference between evaporation and precipitation in May and main growth periods. However, the negative correlation was influenced by the soil water content before sowing. The greater the soil water content before sowing, the higher the spring wheat yield was under the same atmospheric evaporation condition, and vice versa. The spring wheat yield had a positive correlation with the precipitation in May and the soil water content before sowing. Under the same precipitation amount, the higher the soil water content before sowing, the higher the spring wheat yield was. Under the same soil water content, the drier the atmosphere in main wheat growth periods, the lower the wheat yield was. The effective water supply could explain 60.4% of the yield variation, and the water consumption could explain 93.4% of the yield variation. Furthermore, the temperature had no direct impact on the spring wheat yield in the study area, but it might affect the spring wheat yield formation through air saturation deficit.