测墒补灌条件下施氮量对冬小麦耗水特性和水氮利用效率的影响

为明确黄淮麦区冬小麦高产节水条件下的适宜施氮量,以小麦品种山农23为材料,在大田拔节期和开花期0~40cm土壤含水量分别补灌至田间持水量的70%和65%条件下,设置每公顷施纯氮0kg(N0)、180kg(N1)、240kg(N2)、300kg(N3)4个施氮水平,研究小麦耗水特性和水氮利用效率对施氮量的响应。结果表明,N2处理较N0和N1处理显著提高了20~160cm土层土壤贮水消耗量,但与N3处理无显著差异。N2处理灌水量较N0和N1处理分别降低7.35%和9.51%,显著提高土壤贮水消耗量、开花至成熟阶段的耗水量和耗水模系数;N3处理的灌水量较N2处理增加9.59%,两个处理间土壤贮水消耗量、开花至成熟阶段的耗水量和耗水模系数均无显著差异。N2处理的籽粒产量、降水利用效率和灌水利用效率比N1处理分别高9.53%、9.54%和21.04%,施氮量增加至300kg·hm-2时,籽粒产量无显著变化,灌水利用效率和氮肥偏生产力分别降低7.55%和18.94%。因此,在本试验条件下,施氮240kg·hm-2的增产、水氮高效利用效果最佳。

Effect of Nitrogen Application on Water Use Consumption Characteristics and the Water and Nitrogen Use of Winter Wheat under Supplemental Irrigation Based on Measuring Soil Moisture

To clarify the appropriate nitrogen application rate for high-yielding and water-saving of winter wheat production in Huang-Huai winter wheat region,field experiment was conducted under the condition of the relative soil moisture content at jointing and anthesis stages being 70% and 65%. Wheat cultivar Shannong 23 was supplied with nitrogen fertilizer at 0 (N0),180 (N1),240 (N2),and 300 (N3) kg N·hm^-2. We explored the water consumption characteristics and water and nitrogen use efficiencies in response to different nitrogen application rate. The results showed that the consumption amount of soil water in 20-160 cm soil layers for treatment N2 was significantly higher than that of treatment N0 and N1,but no significant difference was found when compared with N3. Compared to treatment N0 and N1,N2 decreased the irrigation water amount by 7.35% and 9.51%,respectively,and significantly increased the soil water consumption,water consumption and water consumption percentage from jointing to anthesis. When the N application rate reached to 300 kg·hm^-2,irrigation water amount was increased by 9.59%,and no significant difference was found under N2 treatment in soil water consumption,water consumption and water consumption percentage from jointing to anthesis. Compared to N1 treatment,N2 increased the grain yield,water use efficiency of precipitation and irrigation water productivity by 9.53%,9.54% and 21.04% respectively. While N application rate reached to 300 kg·hm^-2,there was no significant difference under N2 treatment in grain yield. Irrigation water use efficiency and nitrogen partial productivity were decreased by 7.55% and 18.94%,respectively. Therefore,the optimal N application rate was 240 kg·hm^-2 (N2) under the present experimental conditions.