利用产量差距方法进行华北冬小麦产量受气候影响规律的分析--以河北省栾城县为例

为了进一步分析华北气候要素对小麦产量的影响,基于地处华北腹地的中国科学院栾城农业生态系统试验站,采用逐日作物生长动态模型模拟冬小麦生产潜力(Ymp),并计算其与充分灌溉条件下实际产量(Yh)的产量差距(YG),利用相关分析和逐步回归分析,进行Yh、YG与不同时段气候因子的关系分析。结果表明,抽穗前日照时数和各温度因子与YG表现为正相关趋势,而抽穗后日照时数、日较差与YG为负相关趋势。说明生育前期较好的光温条件更多地增加生产潜力,而后期光照、日较差增加可以更好地满足冬小麦旺盛生长的需要,更多地提升冬小麦的实际产量。从实际产量来看,整个小麦发育期多个时段的日照时数和气温日较差对Yh呈正相关的影响趋势,表明生长季较高的光照和日较差条件对冬小麦实际产量有利。几乎整个发育期降水量与YG表现出负相关趋势,但与充分灌溉条件的Yh相关不显著,说明降水对YG的影响主要在于对生产潜力的减少作用。只有6月上旬降水量与YG呈显著正相关,与Yh有较弱负相关,说明接近成熟时降水对充分灌溉条件的小麦产量可能有不利影响。

Determining the effects of climate on winter wheat yield in Northern China via yield gap analysis-A case study of Luancheng County, Hebei Province

In order to determine the effect of climate on winter wheat yield in the North China Plain, potential wheat productivity (Y_mp) was simulated using daily dynamic crop growth model and agro-climate data from the Luancheng Agro-Ecosystem Experimental Station of Chinese Academy of Sciences. Yield gap (YG) was calculated as the difference between Y_mp and the actual yield under sufficient irrigation (Y_h). A correlative stepwise regression analysis was used to determine the relationship between climate factors at different growth stages and YG. The same analysis was used to determine the relationship between climate factors and Y_h. Before heading, sunshine hours and temperature factors (mean air temperature, maximum air temperature, minimum air temperature and daily temperature-range) were positively related with YG. After heading, however, both sunshine hours and daily temperature-range tended to be negatively correlated with YG. The results suggested that higher light and temperature increased production potential in the early growth stage. At the late stage, however, sufficient sunshine and large daily temperature-range benefited actual yield by enhancing vigorous growth. For actual yield, sunshine hours and daily temperature-range were positively correlated with Y_h at most growth stages. This suggested that high sunshine and daily temperature-range were favored actual yield. While precipitation was negatively correlated to YG for almost the whole growth period, it was not significantly correlated with Y_h. This suggested that precipitation influenced yield gap by reducing production potential. Only at the late ripening stage (about ten days before harvest) was precipitation positively correlated with YG and slightly negatively related with Y_h. It implied that at late ripening stage, winter wheat yield did not benefit from precipitation.