不同施氮水平下增密对玉米产量及抗倒伏性状的影响

本文旨在探究不同施氮水平下增密对玉米产量及抗倒伏性状的影响,为制定大田玉米的种植密度和施氮量提供理论依据。试验结合两种玉米品种、两种密度、三种施氮水平,分析比较不同处理对玉米产量、抗倒伏性状及经济效益的影响。结果表明,本试验条件下品种之间相比,‘北青340’在产量、茎粗及抗折力方面均处于较高水平,故‘北青340’在产量和抗倒伏方面都要强于‘登海605’。干物质量出现差异后,各生育阶段干物质均表现为N₁₈₀>N₃₆₀>N₀;株高、穗位高不能单独作为判断倒伏性能的标准,基部节间茎秆抗折力的提高可以降低作物长高带来的倒伏风险。增密提高了经济效益,同时也增加了倒伏风险;相同密度条件下,抗倒伏性状在N₁₈₀水平下表现最好,不施或者过量施肥反而会提高玉米的倒伏风险。

Effects of Densification on Corn Yield and Lodging Resistance Under Different Nitrogen Levels

The paper aims at exploring the effect of density increasing on corn yield and lodging resistance under different nitrogen application levels, so as to provide a basis for establishing planting density and nitrogen application amount of corn in field. With two corn varieties, two densities and three nitrogen levels, we studied the effects of different treatments on yield, lodging resistance and economic benefits. The results showed that the yield, stem diameter and bending resistance of ‘Beiqing 340’ were higher than those of ‘Denghai 605’. Under the condition of high density, the yield of ‘Denghai 605’ was significantly reduced by applying excessive nitrogen fertilizer. The dry matter of each growth stage was N₁₈₀ > N₃₆₀ > N₀; plant height and ear height could not be used as the standard for judging lodging performance alone, and the improvement of basal internode stem bending resistance could reduce the lodging risk that increased with the crop growth. To increase the planting density would raise the economic benefits as well as the lodging risk. Under the same density, the lodging resistance was the best at N₁₈₀ level, no or excessive fertilization would both increase the lodging risk.