长期定位施氮条件下种植密度对冬小麦石4366品质和氮肥利用的影响

为探究长期施氮条件下种植密度对冬小麦品质特性和氮肥利用的调控作用，在长期定位试验的基础上，2020-2021年度采用裂区试验设计，主区为施氮量，设75 kg·hm^-2（N75）、150 kg·hm^-2（N150）、225 kg·hm^-2（N225）和300 kg·hm^-2（N300） 4个水平；副区为种植密度，设225×10⁴ 株·hm^-2（D225）、300×10⁴株·hm^-2（D300）、375×10⁴株·hm^-2（D375）、450×10⁴株·hm^-2（D450）和525×10⁴株·hm^-2（D525）5个水平；分析了不同施氮条件下种植密度对石4366产量、粉质特性、RVA特性、拉伸特性及氮肥利用率的影响。结果表明，不同施氮量和密度组合下籽粒产量和品质相关指标有较大差异，施氮量对氮肥农学效率和氮肥偏生产力有显著影响。小麦产量随着施氮量的升高而增加，施氮量225 kg·hm^-2、密度范围375×10⁴~525×10⁴株·hm^-2和施氮量300 kg·hm^-2、密度范围225×10⁴~450×10⁴株·hm^-2组合下均能获得较高产量。蛋白质含量、容重和湿面筋含量随着施氮量增加呈升高趋势；稳定时间和粉质质量指数随着施氮量增加呈先升高后降低的趋势，N225下粉质参数最高。小麦籽粒品质和面粉粉质指标均随种植密度的增加而增加。施氮量225 kg·hm^-2、密度525×10⁴株·hm^-2组合是小麦粉质指标最优组合。淀粉RVA参数在施氮量225 kg·hm^-2、密度225×10⁴株·hm^-2处理下最好。拉伸特性在施氮量225 kg·hm^-2、密度450×10⁴~525×10⁴株·hm^-2组合和施氮量300 kg·hm^-2、密度225×10⁴株·hm^-2组合下较好。氮肥农学效率和氮肥偏生产力在施氮量225 kg·hm^-2、密度375×10⁴~525×10⁴株·hm^-2组合下较高。综合籽粒产量、品质相关指标和氮肥利用效率的结果，本试验条件下，施氮量225 kg·hm^-2、种植密度450×10⁴~525×10⁴株·hm^-2可作为石4366高产、优质的较佳肥密组合。

Effect of Planting Density on Quality Characteristics and Nitrogen Utilization of Winter Wheat Shi 4366 under Long-Term Positioning Nitrogen Application

In order to explore the effects of different soil fertility and planting density on the quality characteristics and nitrogen utilization efficiency of Shi 4366,split-plot experiment design was adopted during 2020-2021. The soil fertility was main plot,and density was subplot. Four levels of nitrogen application(urea,46.4%) were set up: 75 kg·hm^-2(N75),150 kg·hm^-2(N150),225 kg·hm^-2(N225) and 300 kg·hm^-2(N300). The planting density was 225×10⁴plants·hm^-2(D225),300×10⁴plants·hm^-2(D300),375×10⁴plants·hm^-2(D375),450×10⁴plants·hm^-2(D450) and 525×10⁴plants·hm^-2(D525). The effects of different nitrogen application and planting densities on the yield,flour properties,RVA properties,tensile properties and nitrogen utilization efficiency of Shi 4366 were studied. There were significant differences in grain yield,quality,nitrogen agronomic efficiency and nitrogen partial fertilizer productivity under different soil fertility and planting density. Wheat yield increased with the increase of nitrogen application. Higher yield was achieved under the combination of N225,375×10⁴-525×10⁴plants·hm^-2 and N300,density ranging from 225×10⁴plants·hm^-2 to 450×10⁴plants·hm^-2. The protein content,bulk density and wet gluten content showed an increasing trend with the increase of nitrogen application. With the increase of nitrogen amount,the trend of stability time and flour quality index increased first and then decreased,and the flour parameters of Shi 4366 was the highest under N225 treatment. The quality of grain and flour increased with the increase of planting density. The nitrogen 225 kg·hm^-2 and 525×10⁴plants·hm^-2 was the best combination treatment for flour quality. Starch RVA parameters were the best under nitrogen fertilizer of 225 kg·hm^-2 and density of 225×10⁴plants·hm^-2. The extension properties were better under the combination of nitrogen 225 kg·hm^-2,450×10⁴-525×10⁴plants·hm^-2 and nitrogen 300 kg·hm^-2,225×10⁴plants·hm^-2. The nitrogen agronomic efficiency and nitrogen partial fertilizer productivity were higher under the combination of nitrogen 225 kg·hm^-2 and 375×10⁴-525×10⁴plants·hm^-2. Based on the results of grain yield,quality related properties and nitrogen use efficiency,225 kg·hm^-2 nitrogen treatment and 450×10⁴-525×10⁴plants·hm^-2 treatments can be used as the better combination of high yield and quality of Shi 4366.