氮肥和密度互作对冬小麦石4366群体、茎秆特性和产量的影响

为探索施氮量和种植密度互作对冬小麦品种石4366生长特性的影响，2020-2021年度在长期氮肥定位试验田通过裂区试验，设置4个施氮水平(施氮量分别为75 kg·hm^-2、150 kg·hm^-2、225kg·hm^-2和300 kg·hm^-2,分别用N75、N150、N225和N300表示)和5个种植密度水平(分别为225×10⁴株·hm^-2、300×10⁴株·hm^-2、375×10⁴株·hm^-2、450×10⁴株·hm^-2和525×10⁴株·hm^-2,分别用D225、D300、D375、D450和D525表示),比较分析了不同处理间该品种旗叶面积、穗部发育、群体动态、秸秆特性和产量的差异。结果表明，施氮量和种植密度对石4366群体、茎秆特性和产量均有显著影响。N75条件下穗长、总小穗...

Effects of Nitrogen-Density Interaction on Population,Stem Characteristics and Yield of Winter Wheat Cultivar Shi 4366

This study was conducted to explore the effects of different nitrogen fertilizer rates and planting densities on the growth characteristics of a winter wheat variety Shi 4366 in a long-term nitrogen positioning test field. Using a split-plot design,a field trial was conducted in 2020-2021,with four nitrogen levels (75 kg·hm_-2,150 kg·hm_-2,225 kg·hm_-2,and 300 kg·hm_-2,represented by N75,N150,N225,and N300,respectively) and five planting density levels (225×10⁴ plants·hm_-2,300×10⁴ plants·hm_-2,375×10⁴ plants·hm_-2,450×10⁴ plants·hm_-2,and 525×10⁴ plants·hm_-2,represented by D225,D300,D375,D450,and D525,respectively). The differences of flag leaf areas,ear development,population dynamics,stem characteristics,yield and economic efficiency among different treatments were analyzed. The results showed that the population,stem characteristics and yield were significantly affected by the nitrogen amount and planting density. The panicle length,total spikelet number and flag leaf area were the smallest under N75 treatment,which were significantly different from those under other nitrogen levels. The panicle length and the total number of spikelet were the most,but the number of sterile spikelet was the least under N225D375 treatment. The filling degree of the basal second internode was the maximum under N150 and N225,and the third internode was the highest under N225. There was no significant difference in the filling degree of the second and the third internodes,with the value lowest under both low nitrogen application and high nitrogen conditions,indicating that insufficient nitrogen supply or excessive nitrogen application were not favorable to the stem development of Shi 4366. The filling degree of the three basal internodes were lower under the conditions of D450 and D525; the value under D525 was the lowest,and the thickness of the stem wall was also the smallest. Under N300D450,the highest population,the number of panicles at maturity and the rate of panicle were the highest. The yield was the highest under N300 but lowest under N75. Meanwhile,the yield was the highest under D525 but lowest under D225. There was no significant difference in the grain number between N150 and N300; and the grain number was the lowest,but the 1 000-grain weight was the maximum under N75. Comprehensive analysis showed that there was a significant interaction between nitrogen application rate and panting density. In this experiment,under the nitrogen fertilizer and planting density of N225D525 and N300D300,the yield and stem characteristics of Shi 4366 can be simultaneously improved,and a higher economic benefits can be obtained at the same time.