追氮量与密度互作对弱筋小麦产量、品质及氮素利用的影响

Effects of Nitrogen Topdressing and Density Interaction on Yield,Quality and Nitrogen Utilization of Weak Gluten Wheat

为了解追氮量与种植密度在弱筋小麦高产优产中的调节作用,以小麦品种扬麦15为材料,设置5个追氮水平(0、54、48.6、43.2和37.8 kg·hm^(-2),分别用N0、N1、N2、N3、N4表示)和3个种植密度(1.8×10^(6)、2.4×10^(6)和3.0×10^(6)株·hm^(-2),分别用D1、D2、D3表示),使用15 N示踪分析技术研究不同追氮水平和种植密度对小麦产量、品质及氮素吸收利用的影响。结果表明,追氮量在0~54 kg·hm^(-2)范围内,小麦开花期植株、成熟期营养器官、成熟期籽粒的氮素积累量均随着追氮量的减少而显著降低,随种植密度的增加而显著上升,且氮素积累量中来源土壤氮的比例大于肥料氮,追施氮肥比例大于基施氮肥。在D1条件下,随追氮量的降低,小麦氮肥生产效率、氮肥利用率、有效穗数和产量均显著降低。在D2和D3条件下,随追氮量的降低,肥料氮转运效率、氮肥生产效率和产量均呈先升后降趋势,均以N2最大。同一追氮量下,随种植密度的增加,氮肥生产效率、氮肥利用效率、穗数和产量均显著增加。减少追氮量和增加种植密度均会降低小麦籽粒沉降值、湿面筋含量和蛋白质含量,提高淀粉含量。本试验条件下,小麦种植密度为3.0×10^(6)株·hm^(-2),追施氮量为48.6 kg·hm^(-2)可在保证弱筋小麦最佳品质前提下,促进小麦对氮肥的吸收利用,协同提高氮素积累、籽粒产量及氮肥生产效率。

In order to understand the regulatory effect of topdressing nitrogen and planting density on high yield and high quality production of weak gluten wheat,a wheat variety Yangmai 15 was used as the material,and five nitrogen topdressing levels(0,54,48.6,43.2 and 37.8 kg·hm-2,designated as N0,N1,N2,N3,and N4 respectively)and three planting densities(1.8×10^(6),2.4×10^(6),and 3.0×10^(6) plants·hm^(-2),designated as D1,D2,and D3,respectively)were set up.15 N tracer technique was applied to study the effects of different nitrogen topdressing levels and planting densities on yield,quality and nitrogen absorption and utilization of wheat.The results showed that the nitrogen accumulation of wheat plants at flowering stage,vegetative organs at maturity stage and grains at maturity stage decreased significantly with the decrease of nitrogen application rate in the range of 0~54 kg·hm^(-2),but increased significantly with the increase of planting density.The proportion of soil nitrogen in the accumulated nitrogen was greater than that of fertilizer nitrogen,and the proportion of topdressing nitrogen fertilizer was greater than that of basal nitrogen fertilizer.Under the conditions of D1,with the decrease of nitrogen application rate,the nitrogen fertilizer production efficiency,nitrogen fertilizer utilization rate,effective panicle number,and yield of wheat decreased significantly.Under the conditions of D2 and D3,with the decrease of topdressing nitrogen,the fertilizer nitrogen transport rate,nitrogen fertilizer production efficiency and yield all showed a trend of increasing first and then decreasing,and N2 was the largest.Under the same nitrogen topdressing amount,with the increase of planting density,nitrogen fertilizer production efficiency,nitrogen fertilizer utilization efficiency,panicle number,and yield increased significantly.Reducing nitrogen topdressing and increasing planting density reduced wheat grain sedimentation value,wet gluten content,and protein content,but increased starch content.Under the conditions of this experiment,the optimal planting density was 3.0×10^(6) plants·hm^(-2),and the optimal nitrogen application rate was 48.6 kg·hm^(-2).Under the premise of ensuring the best quality of weak gluten wheat,it promoted the absorption and utilization of nitrogen fertilizer by wheat,and then synergistically improved nitrogen accumulation,grain yield and nitrogen production efficiency.