干旱灌区土壤水分效应评析

Evaluation of Soil Water Effect in Arid Irrigated Area

为探究干旱区新疆滴灌、常规灌模式农田水分效应问题,基于典型灌区两年定位观测705,950土壤含水率信息,采用灌溉理论及数理统计检验评析表明:1) 北疆三屯河、东疆吐鲁番高昌和南疆于田灌区,农田土壤含水率消长适宜作物需水要求。2) 作物生长期土壤湿度50%以上且≥60%概率为0.85,土壤干湿状态利于作物生长。3) 土壤贮水量、占田间持水量60%以上有效水存量概率≥0.80,呈现耕层少,50~60 cm土层以下增多,滴灌耕层有效水分比常规沟畦灌少,下层滴灌和常规灌溉保持较多,利于作物根系汲取深层水分。4) 北疆灌区中、重壤土质滴灌田间用水定额42 mm,畦灌57 mm,滴灌比畦灌减少26%;东疆吐鲁番高昌灌区粘性及沙壤葡萄沟灌,田间用水定额45 mm,滴灌沙壤土22 mm,滴灌比沟灌减少51%;南疆于田灌区核桃套种小麦畦灌轻沙壤,田间用水定额38 mm。灌水后水量80%在40~60 cm土层,滴灌50 cm及以下,常规灌70 cm及以下。农田灌溉水分运行状态,为节水灌溉用水管理提供了依据。

In order to explore the effect of drip irrigation and conventional irrigation on farmland water content in arid regions of Xinjiang, based on two-year positioning observation of 705,950 soil water content information in typical irrigation areas, irrigation theory and mathematical statistics were used to test and evaluate the results: 1) In Santun River of Northern Xinjiang, Gaochang of Turpan in East Xinjiang and Yutian Irrigation Area of Southern Xinjiang, the growth and decline of farmland soil water content were appropriate to crop water requirement. 2) The probability of soil moisture more than 50% and more than 60% is 0.85. The dry and wet state of soil is beneficial to crop growth. 3) The probability of soil water storage and effective water storage which accounts for more than 60% of field water capacity is more than 0.80. It shows that there are fewer tillage layers, more below 50 - 60 cm soil layers, less effective water in drip irrigation tillage layers than conventional furrow irrigation, and more drip irrigation and conventional irrigation in lower layers, which is beneficial for the root system to absorb deep water. 4) The field water use quota of drip irrigation for medium and heavy loam soil in Northern Xinjiang is 42 mm, and that for border irrigation is 57 mm, which is 26% less than that for border irrigation;the field water use quota for sticky and sandy loam grape furrow irrigation in Gaochang Irrigation Area of Turpan, East Xinjiang is 45 mm, and drip irrigation for sandy loam soil is 22 mm, which is 51% less than furrow irrigation;the field water use quota for walnut interplanting with wheat border irrigation for light sandy soil in Southern Xinjiang is 51%. Field water use quota is 38 mm. After irrigation, 80% of the water is in 40 - 60 cm soil layer, drip irrigation is 50 cm or less, and conventional irrigation is 70 cm or less. The running state of irrigation water in farmland provides a basis for water-saving irrigation water management.