水分亏缺和施氮对春小麦生长和水氮利用的影响

Effect of Water Deficit and Nitrogen Rate on the Growth, Water and Nitrogen Use of Spring Wheat

为探寻促进春小麦生长、增产和水氮高效利用的水氮调控模式,通过田间试验,以春小麦品种永良4号为研究对象,设置4个水分条件[苗期-拔节期亏水(W1:土壤含水率下限为55%的田间持水率)、孕穗期-开花期亏水(W2:土壤含水率下限为60%的田间持水率)、灌浆期-成熟期亏水(W3:土壤含水率下限为55%的田间持水率)、全生育期不亏水处理(W4:三个生育阶段土壤含水率下限分别为70%、70%和65%的田间持水率,对照)]和3个施氮水平(N1:120 kg·hm^(-2);N2:180 kg·hm^(-2);N3:240 kg·hm^(-2)),研究了不同生育时期水分亏缺和施氮对河西地区滴灌春小麦的生长、产量和水氮利用的影响。结果表明,随着施氮量的增加,春小麦的株高、叶面积指数、干物质积累量、产量、水分利用效率(WUE)、灌溉水利用效率(IWUE)和氮肥偏生产力(NFP)均呈现先增后减的趋势,其中N2的平均水分利用效率明显大于N1和N3。不同亏水灌溉对春小麦的生长、产量和水分利用效率等指标有不同的影响,W3和W4更有利于春小麦的生长,但其水分利用效率明显低于W1和W2,W2的平均水分利用效率比W1、W3、W4分别高7.4%、11.7%和12.0%。在所有处理中,N2W2处理获得最高产量和较高的水氮利用效率,因此在河西地区滴灌条件下,可将该水氮组合作为最佳的灌水施氮策略。

The aim of this project was to explore suitable regulation model for high-yield and high-efficiency water and fertilizer use of spring wheat. Field plot experiments were carried out with the spring wheat variety of Yongliang 4. There are four moisture conditions treatments were set up[seedling to jointing(W1:The minimum soil moisture was 55% of field water holding capacity);booting to flowering(W2:The minimum soil moisture was 60% of field water holding capacity);filling to maturity(W3:The minimum soil moisture was 55% of field water holding capacity) and full irrigation at whole growth stage(W4:The minimum soil moisture were 70%, 75%, and 65% of field water holding capacity, respectively for the three growth stages as control)], and three nitrogen rate levels(N1:120 kg·hm^-2;N2:180 kg·hm^-2;N3:240 kg·hm^-2). The effects of water deficit and nitrogen application at different growth stages on the growth, water and nitrogen use efficiency of spring wheat under drip irrigation in Hexi area were studied. The results showed that with the increase of nitrogen rate, the growth, dry matter, yield, WUE, IWUE and NFP were increased first and then decreased. The average WUE of N2 is significantly greater than that of N1 and N3. Different water treatments had different effects on the growth, yield and WUE of spring wheat. W3 and W4 treatments were more beneficial to the growth of spring wheat, but the WUE of W3 and W4 treatments was significantly lower than that of W1 and W2. The average WUE of W2 was 7.4%, 11.7%, and 12.0% higher than that of W1, W3, and W4. The results showed that the highest yield and high water and nitrogen use efficiency of N2 W2 was remarkable. Therefore, under drip irrigation conditions in Hexi region, N2 W2 can be used as the best irrigation and nitrogen application strategy for spring wheat production.