为明确不同施氮水平条件下玉米开花后干物质积累、转运分配特征和土壤氮素动态变化规律及其与产量之间的关系,通过连续两年(2015－2016年)在吉林省中部玉米主产区开展田间试验,研究了不同施氮水平(0,70,140,210,280,350 kg/hm2)对玉米产量、开花后干物质积累、转运与分配特征以及土壤无机氮含量动态变化的影响。结果表明,与不施氮肥处理相比,施氮处理2年玉米产量提高幅度分别为12.3%－37.8%(2015年)和13.9%－47.0%(2016年),差异均达显著水平(P<0.05),其中以施氮量210 kg/hm2处理产量最高；随施氮水平的增加,玉米茎干重、叶干重呈上升趋势,而籽粒干重呈先增后降趋势；施氮处理较不施氮肥处理显著提高了玉米开花后不同器官干物质向籽粒的转运量、转运率和营养体对籽粒的贡献率(P<0.05),并使籽粒干物质分配比例增加,其中以施氮量210 kg/hm2处理干物质转运量、转运率、转运贡献率和籽粒干物质分配比例最高；开花期至成熟期,施氮处理较不施氮肥处理显著提高了0－20cm土壤无机氮含量(P<0.05),并随施氮水平的提高而提高,以施氮量350 kg/hm2处理最高。相关分析结果表明,玉米成熟期干物质积累量、转运量与玉米产量及构成因素均呈正相关关系,除玉米穗数外,相关性均达显著或极显著水平；玉米开花后土壤无机氮含量与产量呈极显著的二次曲线关系。综上所述,适宜的施氮量可提高土壤无机氮含量,促进玉米开花后干物质积累与转运,提高籽粒干物质分配比例,最终提高玉米产量。
In order to clarify the relationships between the characteristics of dry matter accumulation, translocation and distribution, the dynamic change of soil nitrogen and yield after anthesis of maize under different nitrogen application levels, a field experiment was conducted to study the effects of different nitrogen application levels (0, 70, 140, 210, 280, 350 kg/hm2) on maize yield, the characteristics of dry matter accumulation, translocation and distribution, and the dynamic change of soil inorganic nitrogen after anthesis of maize at the main producing areas of central Jilin province for two years (2015－2016). The result showed that maize yield was increased significantly (P<0.05) by 12.3%－37.8% (2105) and 13.9%－47.0% (2016) through nitrogen fertilizer application than that of no nitrogen treatment, and the highest value was at nitrogen fertilizer application of 210 kg/hm2. Dry weight of stem and leaf were increased respectively, but dry weight of kernel was increased at first and decreased later with increasing of nitrogen application levels. Nitrogen fertilizer application improved the translocation amount, translocation rate to kernels derived from dry matter accumulation in different organs and contribution rate to kernels from vegetative organs after anthesis of maize significantly (P<0.05), and also increased the distribution proportion of dry matter in kernel. And the highest values were at nitrogen fertilizer application of 210 kg/hm2 respectively than them of no nitrogen treatment. Nitrogen application could enhance inorganic nitrogen content at 0－20 cm soil significantly (P<0.05) from flowering stage to mature stage than no nitrogen application treatment. Soil inorganic nitrogen content increased with the increment of nitrogen application levels, and the highest value was at nitrogen fertilizer application of 350 kg/hm2. The correlation analysis indicated that maize yield and its components had significantly or extremely significantly positive correlations with the amounts of dry matter accumulation and translocation at mature stage except maize spike number. It had extremely significantly quadratic curve between soil inorganic nitrogen content and yield after anthesis of maize. In conclusion, the appropriate amount of nitrogen fertilizer could improve maize yield by increasing inorganic nitrogen content in soil, dry matter accumulation and translocation after anthesis of maize, and distribution proportion to kernel.