Spatial-temporal patterns of winter wheat harvest index in China in recent twenty years | 近二十年中国冬小麦收获指数时空格局

Chinese. 【目的】揭示近20年中国冬小麦收获指数的总体状况、时空格局和主要影响因子。【方法】利用冬小麦农业气象观测站观测资料,采用统计分析方法,计算中国冬小麦收获指数和相关统计参数;分析冬小麦主产省中时间序列完整(1982―2005年)站点收获指数的年际变化趋势,以及收获指数与产量构成因子、秸秆产量的相关关系。【结果】近20年来,中国冬小麦收获指数总体平均值为0.409(±0.069,n=1 522);20世纪80年代为0.378(±0.061,n=428),90年代为0.408(±0.070,n=657),当前为0.440(±0.062,n=437);冬小麦主产省河南、河北和山东的收获指数平均值分别为0.408、0.417和0.410。1982―2005年间,上述冬小麦主产省收获指数在时间序列上显著增加,其中以河南(0.066/10a)最高,山东(0.044/10a)次之,河北(0.032/10a)最小。偏相关分析表明,收获指数与有效穗数、穗粒数和千粒重均呈极显著正相关,收获指数与秸秆产量的偏相关系数最大,与千粒重的相关系数最小,与有效穗数和穗粒数的相关系数介于两者中间,但具有区域差异。【结论】中国冬小麦收获指数表现出明显的时空变化特征。中国冬小麦收获指数增加的主要原因在于秸秆绝对产量的下降,千粒重增加对收获指数的贡献最小,有效穗数和穗粒数对收获指数的贡献介于前两者之间,其贡献率大小有区域差异性。

English. 【Objective】 The purpose of the study is to understand the general condition and spatial-temporal patterns of winter wheat harvest index and identify the main factors that contributed to harvest index (HI) changes of winter wheat in China. 【Method】 With observed data of winter wheat cultivation at agrometeorological stations between 1982 and 2005, HI of winter wheat and its relevant statistical parameters were calculated in different regions of China. Analysis was conducted on the inter-annual variability of winter wheat HI in Henan, Hebei and Shandong. Partial correlation between HI and three yield components and straw biomass were also statistically analyzed. 【Result】 For the recent twenty years, the average HI in China was 0.409 (±0.069, n=1 522), with 0.378 (±0.061, n=428) in 1980s, 0.408 (±0.070, n=657) in 1990s and 0.440 (±0.062, n=437) at present; it was averagely 0.408, 0.417 and 0.410 in Henan, Hebei and Shandong respectively. HI increased temporally in the dominant plantation region of China, at the rate of 0.066/10a (Henan), 0.044/10a (Shandong) and 0.032/10a (Hebei) accordingly. Results of partial correlation analysis showed the most significant negative correlation between harvest index and straw biomass. Significant positive correlation between harvest index and the three yield components were also exists but differed spatially. 【Conclusion】 Winter wheat harvest index showed spatial- temporal variations in China. Decreasing straw biomass contributed the most to harvest index gain, while 1000-kernel-weight contributed the least; the number of spikes and kernels per spike influenced harvest index in a positive but spatially different way.