摘要：

为给杂交小麦高产栽培过程中合理的氮肥运筹提供理论依据和技术支撑,研究施氮量对二系杂交小麦产量形成、干物质积累分配、氮素吸收利用以及对小麦肥料氮吸收比例的影响,于2020—2021年以3个二系杂交小麦组合和1个常规品种作为材料,采取裂区设计,氮素处理(¹⁵N标记尿素)为主区,品种为副区,设置N0、N120、N180、N240这4个施氮水平试验,分析测定了开花期和成熟期不同处理下小麦各器官的干物质积累分配、植株氮素吸收利用以及籽粒产量。结果表明,施氮量、组合(品种)对小麦产量和产量构成要素的影响达极显著水平。与常规品种京冬17相比,京麦21、BH9613的平均产量分别增加10.47%,4.07%,主要原因是其穗数和穗粒数较高。氮肥施用显著提高了小麦穗数和穗粒数,但降低了千粒质量。4个组合(品种)增施氮肥均显著提高了小麦开花期和成熟期干物质积累量,开花期小麦各器官干物质量表现为茎秆>叶>穗,成熟期为籽粒>茎秆>颖壳+穗轴>叶。不同施氮量下组合的氮素农学利用率、氮素偏生产力平均值表现为:京麦21>BH9613>京冬17>BH3606,与产量趋势一致。4个组合(品种)的¹⁵N原子百分超、来自肥料氮含量及占比均表现为:籽粒>秸秆,并随着施氮量的增加而显著增加。与京冬17相比,3个杂交组合(品种)来自土壤氮的占比显著提高,从氮利用角度说明杂交小麦耐瘠薄性更强。综合分析,N240施氮量综合表现优于其他施氮量的表现,京麦21和BH9613这2个杂交组合(品种)的综合表现优于对照京冬17。

关键词: 二系杂交小麦, 施氮量, 干物质积累量, 氮素分配利用, 产量, ¹⁵N尿素

Abstract:

To provide theoretical basis and technical support for rational nitrogen fertilizer management in high-yield cultivation of hybrid wheat,this study aims to investigate the effects of nitrogen application rate on yield formation,dry matter accumulation and distribution,nitrogen absorption and utilization,as well as the nitrogen absorption ratio of wheat fertilizers in two-line hybrid wheat.From 2020 to 2021,three two-line hybrid wheat combinations and one conventional variety were used as materials.A split plot design was adopted,with nitrogen (labeled with ¹⁵N urea) treatment as the main zone and varieties as sub zones.Four nitrogen level experiments were set up at N0,N120,N180,and N240.The dry matter accumulation and distribution,plant nitrogen absorption and utilization,and grain yield of wheat organs were analyzed and measured under different treatments during the flowering and maturity stages.The results demonstrated that a highly significant effect of nitrogen application rate and combination (variety) on wheat yield and yield components.Compared with the conventional varieties Jingdong 17,the average yield of Jingmai 21 and BH9613 increased by 10.47% and 4.07% respectively,mainly due to their higher number of spikes and grains per ear.The application of nitrogen fertilizer significantly increased the number of spikes and grains per ear of wheat,but reduced the thousand grain weight.The application of nitrogen fertilizer to four varieties significantly increased the accumulation of dry matter in wheat during the flowering and maturity stages.The dry matter weight of various organs in wheat during the flowering stage was as follows:stem>leaf>spike,and during the maturity stage,it was as follows:grains>stem>spike-stalk+glume >leaf.The average values of nitrogen fertilizer agronomic utilization efficiency and nitrogen fertilizer partial productivity under different nitrogen application rates were as follows:Jingmai 21>BH9613>Jingdong 17>BH3606,which was consistent with the yield trend.The ¹⁵N atomic percentage of the four combinations (varieties),the nitrogen content from fertilizer,and the proportion of nitrogen from fertilizer all showed the following order:grains>straw,and they significantly increased with the increase of nitrogen application rate.Compared with Jingdong 17,the proportion of soil nitrogen in the three hybrid combinations (varieties) significantly increased,indicating that hybrid wheat had stronger tolerance to barrenness from the perspective of nitrogen utilization.After comprehensive consideration and analysis,the nitrogen application rate of N240 significantly increased wheat yield compared to other treatments,making it the optimal nitrogen fertilizer application rate for wheat cultivation.The comprehensive performance of the two hybrid combinations (varieties) of Jingmai 21 and BH9613 is better than the performance of the control Jingdong 17.

Key words: Two-line hybrid wheat, Nitrogen application rate, Dry matter accumulation, Nitrogen allocation and utilization, Yield, ¹⁵N urea