This study aimed to explore nitrogen fertilizer management measures to synergistically improve wheat yields and water and nitrogen use efficiency under supplemental irrigation based on soil moisture in the Huang Huai winter wheat area. Wheat variety "Yannong 1212" was used as the test material. There were three nitrogen application levels, 150 kg·hm-2 (N1), 210 kg·hm-2 (N2), and 270 kg·hm-2 (the conventional nitrogen application rate in the Huang Huai winter wheat area, N3), with the relative soil water content of 0-40 cm of each treatment was supplemented to 70% at the jointing and flowering stages. We investigated the effects of nitrogen rates on photosynthetic characteristics of flag leaves after flowering, 13C assimilate accumulation and transport, and water and nitrogen use efficiency after flowering of wheat. The results showed that photosynthetic capacity of flag leaves in the N2 and N3 was significantly higher than that in N1 14-35 days after flowering, and that there was no significant diffe-rence between N2 and N3 treatments. The 13C isotope tracing results showed that the translocation amount of 13C assimilates in vegetative organs in N2 was 12.1% and 7.1% higher than that in N1 and N3, respectively. The distribution amount of 13C assimilates in grains at maturity was 10.1% and 5.3% higher than that of N1 and N3, respectively. The amount of nitrogen fertilizer affected water consumption, water consumption proportion, and total water consumption in different growth stages of wheat. Water consumption during the whole growth period showed no difference between N2 and N3 treatments, but both were significantly higher than that for N1. Water consumption and water consumption proportion of N2 were higher from the jointing to maturity stages, water use efficiency of N2 was 7.5% and 4.8%, and grain yield was 4.7% and 10.9% higher than that of N3 and N1 treatments, respectively. The partial productivity of nitrogen fertilizer was 34.6% higher in the N2 than that of N3. Considering wheat grain yield and water and nitrogen use efficiency, 210 kg·hm-2 nitrogen application was the best rate under water-saving condition of supplementary irrigation after soil moisture measurement in the study area.
为探究黄淮冬麦区测墒补灌节水条件下协同提高小麦产量和水氮利用效率的氮肥管理措施,以小麦品种‘烟农1212'为材料,在拔节期和开花期将各处理0～40 cm土层土壤相对含水量均补灌至70%条件下,设置3个施氮水平,即150(N1)、210(N2)和270 kg·hm-2(黄淮冬麦区常规施氮量,N3),研究施氮量对小麦开花后旗叶光合特性、13C同化物积累与转运及水氮利用效率的影响。结果表明: N2和N3处理开花后14～35 d旗叶光合能力显著高于N1处理,N2与N3处理间差异不显著。13C同位素示踪结果显示,N2处理开花后营养器官13C同化物转运量比N1和N3处理分别高12.1%和7.1%,成熟期13C同化物在籽粒中的分配量比N1和N3处理分别高10.1%和5.3%。施氮量亦调节了小麦不同生育阶段的耗水量、耗水模系数和总耗水量,小麦全生育期耗水量表现为N2与N3处理无显著差异,但均显著高于N1处理,N2处理拔节至成熟期阶段耗水量和耗水模系数均较高。N2处理水分利用效率比N3和N1处理分别高7.5%和4.8%,籽粒产量比N3和N1处理分别高4.7%和10.9%,氮肥偏生产力比N3处理高34.6%。综合考虑小麦籽粒产量和水氮利用效率,施氮量为210 kg·hm-2处理为研究区测墒补灌节水条件下的最佳施氮量。.
Keywords: 13C assimilate accumulation amount; nitrogen application rate; water-nitrogen use efficiency; wheat.