我国北方冬小麦生育期内干旱少雨,农业水资源紧缺,因此,由汛期降水形成的底墒,特别是土壤深层储藏的水分则成为小麦生长的重要水源之一。在中国气象局固城农业气象试验基地大型人工控制农田水分试验场,进行了提高底墒和土壤深层水分利用率,以肥促根觅水的旱作冬小麦田间试验。试验结果表明,施肥深度在20～40cm范围内,能明显促进冬小麦中、下层根系的生长发育,扩大作物觅取水分和养分的土壤空间,有效地吸收和利用储藏在土壤深层的水分,从而能充分发挥土壤水库的调控作用,提高小麦的产量和水分利用效率。

Because of shortage of rainfall and drought during the growth period of winter wheat in northern China,the available soil water(ASW)formed in flood season before planting,parti-cularly water stored in deep soil layer has become one of the important water sources for winter wheat growth.The experiments were conducted in man-controlled water supply field at Gucheng Agrometeorological Experimental Base of China Meteorological Administration(CMA).Two ferti-lizing depth treatments and a contrast(CK)were applied:(1)fertilizing at0～20cm(C1),and(2)fertilizing at20～40cm(C2).We analyzed the effect of different fertilizing depths on the growth of root system,the use of the available soil water before planting,water use efficiency and winter wheat yield.The experimental results indicated:the fertilizing depth of20～40cm can strengthen the growth of root system in mid-layer and deep-layer,therefore the space where wheat may ab-sorb more water and nutrient can be extended.This contributes to effective use of water in deep soil layer,which can bring into play the regulation function of soil reservoir to improve water use efficiency and yield of winter wheat.