测墒滴灌对氮肥调控下冬小麦水分利用效率及灌浆动态的影响

为研究氮肥调控下测墒滴灌对冬小麦水分利用效率及灌浆动态的影响,通过2013-2015年的大田试验,在3个施氮水平(90 kg·hm~(-2)、240 kg·hm~(-2)和350 kg·hm~(-2))下,于冬小麦的播前、拔节期及开花期通过测墒补灌至土壤相对含水量为田间持水量的75%,以全生育期0灌溉及漫灌作为对照,分析了滴灌对冬小麦耗水量、水分利用效率、产量及灌浆特性的影响.结果表明:在滴灌条件下,田间耗水量随滴灌次数的增加而增加,而土壤贮水和降水占总耗水量的比例显著下降,灌溉水所占比例明显提高.施氮量为240 kg·hm~(-2)时,滴灌底墒水、拔节水和开花水的籽粒产量最大,达到10 109.79 kg·hm~(-2),WUE和IUE分别比漫灌显著提高50.52%和68.01%.在整个灌浆过程中,强势粒的灌浆速率均明显高于弱势粒,灌浆参数随施氮量的增加呈现先升高后降低的趋势,测墒滴灌能有效增加冬小麦的终极生长量,并且提高平均灌浆速率,提升灌浆能力.综合看来,施氮量为240 kg·hm~(-2),测墒滴灌底墒水、拔节水和开花水的产量和水分利用率较高,籽粒的灌浆能力较强.

Effect of Drip Irrigation and Nitrogen Regulation on WUE and Grain Filling of Winter Wheat Based on Soil Moisture Measurement

This study aimed to determine a reasonable irrigation scheduling for high yield and water use efficiency( WUE) of winter wheat. A field experiment was carried out with the cultivar of Zhoumai 22 in the Northern Henan province during 2013-2015.Two-factor split plot design was arranged with three replications. The main plots were subjected to the nitrogen regimes,which were applied at three levels: 90 kg·hm~(-2)( D),240 kg·hm~(-2)( Z),and 350 kg·hm~(-2)( G). The subplots consisted of four drip irrigation treatments: drip irrigation at sowing stage( W0),drip irrigation at sowing and jointing stage( W1); drip irrigation at sowing and anthesis stage( W2); drip irrigation at sowing,jointing and anthesis stage( W3). Surface irrigation at sowing,jointing and anthesis stage( CK) under the nitrogen application 240 kg·hm~(-2)were used as the control group. The target relatively soil moisture content was controlled as 75% after measuring 0-100 cm soil moisture. The results showed: Drip irrigation and fertilization treatments significantly hewe effects on the water requirement regularity of winter wheat. The water consumption of drip irrigation was significantly lower than that of CK. The water consumption increased with irrigation times under drip irrigation,and the proportion of soil water storage and precipitation in total water consumption reduced significantly,whereas the proportion of irrigation water obviously increased. The yield increased first then declined with the increased of N application. The yield reached peak of 10 109. 79 kg·hm~(-2)with 240 kg·hm~(-2)N application and W3,and the WUE and IUE significantly increased by 50. 52% and 68. 01% respectively compared with CK. The WUE and IUE reached peak with 240 kg·hm~(-2)N application and W2,significantly increased by 83. 12% and 136. 51% respectively compared with CK,but the yield was slightly lower than that of CK. The filling rate of superior grains was obviously higher than that of inferior grains,and the grain filling parameters firstly increased,then decreased with the increase of nitrogen-application. Comprehensively,drip irrigation at sowing,jointing and anthesis stage based on soil moisture measurement at N application rate of 240 kg·hm~(-2)realized high yield,high WUE,and high grain-filling capacity.