Abstract: In order to find a suitable irrigation system for planting alfalfa in Horqin sandy land,we investigated the yield,quality and water use efficiency,etc,under 5 irrigation quotas and 4 irrigation frequencies treatment in this experiment,respectively. The results showed that the effects of different irrigation quotas on the CP and ADF were significant (P<0.05),and the effects on yield and water use efficiency were significant (P<0.05). The average soil relative water content was 39.43% with the highest annual yield and water use efficiency,and it was the optimal treatment when the irrigation quota was 546 mm. The effects of different irrigation frequencies on yield and water use efficiency were significant (P<0.05). The soil relative water content of irrigation once every 2 days maintained around 42.45%,the annual yield and water use efficiency was the highest,and it was the best irrigation frequency. The relative water content of 0～20 cm soil could be used to judge whether there is water shortage. The optimal relative water content in sand soil area should be kept at about 40%.

Key words: Horqin sandy land, Alfalfa, Irrigation system, Yield, Quality

摘要： 为制定适合在科尔沁沙地种植紫花苜蓿（Medicago sativa L.）的灌溉制度，本试验设2个单因素处理，分别为5个灌溉定额和4个灌溉频率处理，通过分析其产量、品质和水分利用效率等指标，以期制定最合适的灌溉制度。结果表明：不同灌溉定额对紫花苜蓿粗蛋白和酸性洗涤纤维含量的影响差异显著（P<0.05），对产量和水分利用效率的影响差异显著（P<0.05），当灌溉定额为546 mm时，土壤的相对含水量为39.43%，苜蓿的年产量、水分利用效率最高，为最佳灌溉定额。不同灌溉频率对产量和水分利用效率的影响差异显著（P<0.05），2 d灌水1次土壤相对含水量维持在42.45%左右，年产量和水分利用效率最高，为最佳灌溉频率。可以通过0～20 cm土壤相对含水量来判断是否缺水，该地区土壤的最佳相对含水量应保持在40%左右。

关键词: 科尔沁沙地, 紫花苜蓿, 灌溉制度, 产量, 品质