灌溉频率对滴灌小麦土壤水分分布及水分利用效率的影响

Effects of irrigation frequency on soil water distribution and water use efficiency in wheat field under drip irrigation

通过田间试验，研究了不同灌水频率对滴灌小麦农田土壤水分分布及小麦水分利用效率的影响。结果表明：从整个生育期来看，在灌水量375mm条件下，高频灌溉（每4天1次）处理0～40mm土层含水率和土壤贮水量较高，而深层（40～100cm）土壤较低；低频灌溉（每10天1次）处理有利于水分的下渗和侧渗，深层土壤含水率和土壤贮水量较高，但水分补给不及时，表层土壤含水率和贮水量偏低；总体上中频灌溉（每7天1次）处理有利于水分在土壤剖面中的均匀分配，有利于作物生长。中频灌溉产量和水分利用效率都最高，分别比高频灌溉和低频灌溉产量增加7．6％和13．5％，水分利用效率增加2．6％和9．9％。在当地自然气候条件下，滴灌小麦采用375mm灌溉量和每7d1次的灌溉频率是较适宜的灌溉模式。

The field experiment was carried out to investigate the effects of different irrigation frequency （once every 4, 7 and 10 days） on soil water distribution and water use efficiency （WUE） of wheat under drip irrigation in North Xin- jiang. The results showed that, when the irrigation amount was 375 mm, high irrigation frequency （once every 4 days） induced a relatively high water content and water storage in surface soil （0 - 40 cm） during the whole growth season of wheat, but caused an inadequate moisture in deep soil （40- 100 em）, Low irrigation frequency （once every 10 days） was beneficial to the infiltration and lateral seepage of water, and induced a relatively high water content and water stor- age in deep soft, however, the water content and water storage in surface soil was low due to delay of water replenish- ment. Overall, mid irrigation frequency （once every 7 days） was beneficial to the uniform distribution of irrigation water in soil profile and was good for crop growing. Under mid irrigation frequency, the yield of wheat was increased by 7.6 % and 13.5 % respectively, and the WUE was increased by 2.6 % and 9.9 % respectively, compared to those under high and low irrigation frequency. It was suggested that irrigation with an amount of 375 mm and a frequency of once every 7 days be an appropriate drip irrigation mode for wheat under local climate condition.