Abstract: In this study， alfalfa（Medicago sativa L.）was used as the experimental material. Through field control experiments and randomized block design， the effects of irrigation water temperature （surface water and groundwater） and irrigation amount （65%-75% field capacity， 55%-65% field capacity， 45%-55% field capacity） on yield， quality and irrigation water use efficiency of alfalfa were studied. Hay yield， irrigation water use efficiency， crude protein， ash， acid detergent fiber content and relative feeding value of alfalfa were analyzed， and the irrigation methods with high yield， high quality and high water efficiency of alfalfa were determined， in order to provide theoretical basis and practical guidance for optimizing irrigation management and efficient production of alfalfa. The main results are as follows， compared with groundwater irrigation， surface water irrigation significantly increased hay yield （17.36%-21.72%）， crude protein content （4.98%-7.07%）， crude ash content （0.47%-1.25%） and relative feeding value （3.61%-5.53%）， and decreased acid detergent fiber content （1.06%-2.98%） and neutral detergent fiber content （1.97%-4.42%）. Under mild drought stress， crude protein （20.33%）， crude ash （8.22%）， acid detergent fiber （22.48%）， neutral detergent fiber （39.96%） and relative feeding value （168.75） reached the optimal value. The irrigation water use efficiency of surface water treatment was the highest （2.73 kg·m^-3） under severe drought stress. Groundwater and severe drought stress synergistically inhibited root physiological activity， aggravated the decrease of yield and quality， and reduced water use efficiency.

Key words: Irrigation water temperature, Irrigation amount, Hay yield, Irrigation water use efficiency, Nutritional quality of alfalfa

摘要： 本研究以紫花苜蓿（Medicago sativa L.）为试验材料，通过田间控制试验，采用随机区组设计，开展了灌溉水温（地表水与地下水）和灌溉量（65%~75%田间持水量，55%~65%田间持水量，45%~55%田间持水量）的变化对产量、品质及灌溉水利用效率影响的研究。分析了干草产量、灌溉水利用效率以及粗蛋白、灰分、酸性洗涤纤维含量、相对饲喂价值等指标，确定了紫花苜蓿高产、高品质、高水效的灌溉方式，以期为优化苜蓿灌溉管理和高效生产提供理论依据和实践指导。主要研究结果如下：地表水较地下水灌溉显著提高了干草产量（17.36%~21.72%）、粗蛋白含量（4.98%~7.07%）、粗灰分含量（0.47%~1.25%）及相对饲喂价值（3.61~5.53），降低了酸性洗涤纤维含量（1.06%~2.98%）和中性洗涤纤维含量（1.97%~4.42%）；轻度干旱胁迫下粗蛋白（20.33%）、粗灰分（8.22%）、酸性洗涤纤维（22.48%）、中性洗涤纤维（39.96%）和相对饲喂价值（168.75）达最优值。重度干旱胁迫下地表水处理灌溉水利用效率最高（2.73 kg·m^-3）。地下水与重度干旱胁迫协同抑制根系生理活性，加剧产量和品质下降并降低水分利用效率。

关键词: 灌溉水温, 灌溉量, 干草产量, 灌溉水利用效率, 苜蓿营养品质