中文摘要：

为了提高西北干旱地区作物的水分利用效率,研究了膜下滴灌条件下,不同土壤基质势对辣椒产量、耗水和水分利用效率的影响.试验根据滴头下25 cm深处土壤的基质势设置5个控水下限：- 10、-20、-30、-40kPa和- 50 kPa,测量指标主要有气象要素、土壤水分特性曲线、土壤基质势、土壤水分、辣椒产量和单果重等.试验结果表明,基质势下限控制在- 10～ -40 kPa之间对产量影响较小,但是当基质势下限降至- 50 kPa时会导致严重减产,灌水量与辣椒腾发量一般随着基质势控制下限的降低而逐渐减少,水分利用效率随着基质势控制下限的降低呈现先升高再降低的趋势.土壤基质势下限控制在-30～ -40 kPa时辣椒产量和水分利用效率均较高,因此建议在西北干旱地区膜下滴灌条件下辣椒的基质势控制下限宜为- 30～-40 kPa.

英文摘要：

For increasing water use efficiency in the arid areas of Northwest China, a field experiment was conduct- ed to study the effects of different soil matric potentials（SMP） on pepper yield, water consumption and water use efficien- cy under mulched drip irrigation. Five treatments were evaluated based on the soil matric potentials at 25 cm depth, and they were - 10 kPa, - 20 kPa, - 30 kPa, - 40 kPa and - 50 kPa. The measured data included meteorological ele- ments, soil water characteristic curves, soil matric potential, soil water content, yield and the weight of each pepper fruit. The results showed that controlling SMPs between - 10 kPa and - 40 kPa made minor effect on pepper yield, while pepper yield decreased greatly for controlling SMP of - 50 kPa. Crop evaportranspiration and irrigation water amount dropped with the decreasing of SMP. Water use efficiency increased first with the decreasing of SMP and dropped then as controlling SMP of - 50 kPa. Crop yield and water use efficiency were higher for controlling SMP of - 30 kPa to - 40 kPa. Theretbre, a SMP range of - 30 kPa to - 40 kPa was recommended for scheduling drip-irrigated pepper un- der plastic mulching condition in the arid areas of Northwest China.