减量施氮对滴灌春小麦干物质和氮素积累转运特征的影响

为探明新疆滴灌春小麦氮高效利用特征,于2019年采用田间试验研究了减氮对强筋型小麦品种新春38号和中筋型品种新春49号的干物质和氮素积累、转运及氮素利用效率的影响。结果表明,新春38号和新春49号拔节期、开花期、成熟期的各器官及植株的干物质积累量和花前干物质转运效率及其对籽粒产量贡献率随减氮比例的增大呈现先增大后减小的趋势,均在CF_2(较正常施氮减10%)处理下达到最大值;氮素积累量和花前氮素转运量及花后氮素积累量均随减氮比例的增大呈逐渐减小的趋势,均在正常施氮(CK_1)处理下达到最大值;花前氮素转运效率和花前氮素对籽粒氮的贡献率呈增大趋势。新春38号和新春49号的氮肥利用效率均随减氮比例的增大呈先升高后降低的趋势,在CF_2处理下达到最大值,为37.53%和35.91%,比CK_1提高12.36%和10.21%。小麦籽粒产量随施氮量减少呈先增大后减小的趋势,在CF_2处理下最大,与不施氮(CK_2)相比,各施氮处理下小麦籽粒产量均显著增加,新春38号和新春49号分别提高24.04%～39.22%和32.05%～45.38%。综合考虑,推荐较正常施氮减氮10%(CF_2,270 kg·hm~(-2))为新疆滴灌春小麦栽培模式的适宜施氮量。

Effect of Reduced Nitrogen Application on Dry Matter and Nitrogen Accumulation and Transportation Characteristics of Spring Wheat under Drip Irrigation

In order to explore the characteristics of nitrogen efficient utilization of spring wheat under drip irrigation in Xinjiang, the effects of nitrogen reduction on dry matter, nitrogen accumulation, transportation and nitrogen use efficiency of a strong gluten wheat variety Xinchun 38 and a medium gluten wheat variety Xinchun 49 were studied in 2019. The results showed that the dry matter accumulation, pre-anthesis dry matter transport rate and its contribution rate to grain of Xinchun 38 and Xinchun 49 increased first and then decreased with the increase of nitrogen reduction ratio, reaching the maximum value under CF₂ treatment; nitrogen accumulation, nitrogen transport before flowering and nitrogen accumulation after anthesis increased with the increase of nitrogen reduction ratio. The nitrogen transport rate and contribution rate of nitrogen before anthesis increased. The nitrogen use efficiency of the two varieties increased first and then decreased with the increase of nitrogen reduction ratio, reaching the maximum value(37.53% and 35.91%) under CF₂ treatment, 12.36% and 10.21% higher than that of CK₁, respectively. The grain yield of Xinchun 38 and Xinchun 49 were increased by 24.04%-39.22% and 32.05% -45.38%, respectively, compared with that under CK₂. Based on comprehensive consideration, 10% (CF₂, 270 kg·hm^-2) of nitrogen reduction was recommended as the suitable nitrogen application rate for spring wheat in Xinjiang.