作物同一品种长期多点田间试验数据为研究作物产量时空差异提供了有效的数据支撑。定量分析夏玉米同一品种（郑单958）产量及产量构成要素的时空变化特征，探讨造成产量时空差异的气候年型组合的变化特征。本研究基于2004-2013年夏玉米种植区郑单958多点的田间试验数据进行分析。结果表明，夏玉米区域平均产量为9055 kg hm-2，产量年际差为1635 kg hm-2，变幅为18.1%；地点差4258 kg hm-2，变幅为47.1%。区域平均千粒重为313 g，年际变幅为13.1%；地点变幅为27.8%。区域平均穗粒数为479，且呈显著下降趋势（P≤0.01），年际差异变幅为18.0%，地点差异变幅为38.7%。千粒重的增加导致夏玉米产量显著增加。穗粒数显著降低和时空差异大是造成产量波动和时空差异变幅大的主要原因。夏玉米生育期内日最高温度大于33 oC的天数增加造成玉米产量大幅度降低的主要气候因素。
Long-term and multipoint field experimental data with the same cultivar provides effective data support for research spatiotemporal variations of crop yield. This study aimed to quantify the spatiotemporal change of summer maize yield and yield components and explore the change of the year of climate type. The data of multipoint field experiments with the same summer maize cultivar (Zhengdan958) were analyzed in summer maize growing region in China from 2004 to 2013. Summer maize yield of the regional average was 9055 kg ha-1. The seasonal difference of the yield was 1635 kg ha-1, the site difference of it was 4258 kg ha-1. The seasonal and site variation of it was 18.1% and 47.1%, respectively. 1000-kernel weight of the regional average was 313 g with 13.1% seasonal variation and 27.8% spatial variation. Kernel number of the regional average was 479, and decreased significantly (P≤0.01). Kernel number presented 18.0% seasonal variation and 38.7% spatial variation. Summer maize yield increased significantly with the increase of 1000-kernel weight. The large fluctuation and spatiotemporal variation of summer maize yield were caused by kernel number decreasing significantly and the large spatiotemporal variation. The days of maximum temperature above 33 oC was the main reason for summer maize yield greatly reduction during growth stage.