关键词: 春小麦, 灌水量, 水肥分布, 水分利用效率, 层次性土壤

Abstract: The optimal irrigation quota was estimated for spring wheat planted in Shapotou hiberarchy soil, through measuration of soil water and nutrient in soil profile, field evapotranspiration, water use efficiency and bio-indices of spring wheat under conditions of different irrigation quota. The results indicated that: (1) Soil water distributing depth increased obviously with the increase of irrigation quota in jointing and flowering stages of spring wheat; (2) The ranges of distributing peak values of soluble nutrient varied about 0~20 cm, with diminished concentrations along with the increasing of irrigation quota in the jointing stage of spring wheat. In flowering stage, with the increasing of irrigation quota, the depth of the distributing peak values of soluble nutrient moved downwards with maximal soluble nutrient concentration under the 500 m³·hm^-2 irrigation; (3) Consumed water of spring wheat and field actual evaportranspiration increased with the increasing of the irrigation quota, but the water use efficiency(WUE) changed inversely. Compared with the WUE under 500 m³·hm^-2 irrigation quota, the WUE of grain under 750 m³·hm^-2 and (1 000) m³·hm^-2 decreased 83.33% and 147.50%, respectively. So the optimal irrigation quot was about 500 m³·hm^-2 for planting spring wheat on this type soil, which would hold about 40% of field maximal capacity.

Key words: spring wheat, irrigation quot, distribution of water and nutrient, water use efficiency, hiberarchy soil