施氮水平对玉米开花后干物质积累、转运及土壤无机氮含量的影响

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,研究不同施氮水平对玉米产量、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年玉米产量平均增幅为13.1%～42.1%,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,子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玉米开花后不同器官干物质向子粒的转运量、转运率和营养体对子粒的贡献率(P0.05),均以施氮量210 kg/hm2处理为最高。开花期至成熟期0～20 cm土壤无机氮含量,随施氮水平的提高而提高。相关分析表明,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,除穗数外,相关性均达显著水平。因此,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,提高玉米产量。

Effects of Nitrogen Application on Dry Matter Accumulation, Translocation, and Inorganic Nitrogen Content in Soil after Anthesis of Maize

A field experiment was conducted to study the effects of different nitrogen(N) application levels on maize yield, the characteristics of dry matter accumulation, translocation and distribution, and the dynamic change of soil inorganic N 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 by 13.1%-42.1% averagely through N fertilizer application than no N treatment for two years, and the highest value was at N fertilizer application of 210 kg/ha. The dry weight of stem and leaf were increased respectively, but the dry weight of kernel was increased at first and decreased later with increasing of N application levels. N 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 the highest values were at N fertilizer application of 210 kg/ha, respectively than them of no N treatment. Soil inorganic N content at 0-20 cm soil from the flowering stage to mature stage increased with increasing of N application levels. The correlation analysis indicated that maize yield and its components had significantly positive correlations with the amounts of dry matter accumulation and translocation at mature stage except spike number. The appropriate amount of N fertilizer could improve maize yield by increasing inorganic N content in soil, dry matter accumulation and translocation after anthesis of maize.