调亏灌溉对干旱环境下春小麦产量与水分利用效率的影响

Effects of regulated deficit irrigation on grain yield of spring wheat in an arid environment

试验研究调亏灌溉对干旱环境下春小麦产量与水分利用效率的影响结果表明，干旱环境下调亏灌溉春小麦拔节～孕穗后土壤水势低于未进行水分调亏的对照，且全生育期比对照多利用土壤水分14．3～66．5mm。调亏处理小麦产量、穗粒数、水分利用效率与充分供水对照间差异显著，并未因土壤水分亏缺而降低，甚至有较大幅度提高。试验条件下春小麦调亏的适宜土壤水分亏缺水平为营养生长期（拔节）重度水分亏缺（45％～50％田间持水量）．其他生育期（孕穗、抽穗、灌浆期／生理成熟前）充分供水（65％～70％田间持水量），而最佳调亏灌溉定额为330～350mm。干旱环境下调亏灌溉春小麦产量和水分利用效率与全生育期耗水量间均呈二次抛物线关系。

Studies on the regulated irrigation of spring wheat indicate that in an add environment, the soil water potentials of spring wheat are lower in the regulated deficit irrigation treatments than that in the nowaterdeficit control from jointing to booting, and 14.366.5mm more stored soil water is consumed under the regulated deficit irrigation. Significant differences are observed in yield, kernels per spike, and water use efficiency of spring wheat under the regulated deficit irrigation as compared to the control. The yield, kernels per spike, and water use efficiency of wheat are greatly improved rather than inhibited by water deficit. The proper soil water deficits of spring wheat are water deficit（45 96 50% of field capacity） at the vegetative stage（jointing）and free from water deficit at the other growing periods such as booting, heading, and filling to pre-physiological maturity（65 % - 70 % of field capacity）. Correspondingly, the optimum total irrigation water is 330mm to 350mm. In addition, the regression analysis presents quadratic relationships between seasonal evapotranspiration and yield, water use efficiency of spring wheat under the regulated deficit irrigation.