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.

Irrigation water temperature  /  Irrigation amount  /  Hay yield  /  Irrigation water use efficiency  /  Nutritional quality of alfalfa