Abstract: The aim of this study was to investigate the impact of different interaction modes of irrigation methods and phosphorus fertilization on the production performance and nutritional quality of alfalfa (Medicago sativa). Five irrigation methods,including flood irrigation (F),sprinkler irrigation (S),10 cm subsurface drip (D10),20 cm subsurface drip (D20) and 30 cm subsurface drip (D30),and four phosphorus application (P₂O₅) gradients of 0 kg·hm^-2 (P0),60 kg·hm^-2 (P1),120 kg·hm^-2 (P2) and 180 kg·hm^-2 (P3) were set up by two-factor split plot design. The production performance,fodder quality and water and phosphorus use efficiency of alfalfa under water and phosphorus coupling were investigated. The results showed that the soil water content,production index,nutrient index,water use efficiency and phosphorus fertilizer partial productivity were significantly higher in the three drip treatments than in flood and sprinkler treatments. Irrigation methods and phosphorus fertilization levels had significant effects on alfalfa plant height,branch number,hay yield,crude protein content,acid detergent fiber and relative feed value. Principal component analysis showed that the combination of water and phosphorus was the best when P₂O₅ 120 kg·hm^-2 was applied under drip irrigation at 30 cm depth,and the nutritional quality ranked first.

Key words: Alfalfa, Irrigation method, Phosphorus, Production performance, Nutritional quality

摘要： 为探究灌溉方式与磷素的互作模式对紫花苜蓿(Medicago sativa) 生产性能及营养品质的影响，本研究采用双因素裂区设计，设置漫灌(F)、喷灌(S)、地下10 cm滴灌(D10)、地下20 cm滴灌(D20)和地下30 cm滴灌(D30)5种灌溉方式和0 kg·hm^-2(P0)，60 kg·hm^-2(P1)，120 kg·hm^-2(P2)和180 kg·hm^-2(P3) 4个施磷(P₂O₅)梯度。研究水磷耦合条件下苜蓿生产性能、饲草品质和水磷利用效率。结果表明：3种地下滴灌处理的土壤含水量、生产指标、营养指标、水分利用效率和磷肥偏生产力均显著高于漫灌和喷灌处理；灌溉方式和施磷水平对苜蓿株高、分枝数、干草产量、粗蛋白含量、酸性洗涤纤维和相对饲喂价值均有显著影响。通过主成分分析得出，在地下30 cm滴灌方式下，施P₂O₅ 120 kg·hm^-2时的水磷组合模式最好，产量和营养品质综合排名第一，在生产上应用可得到优质牧草。

关键词: 紫花苜蓿, 灌溉方式, 磷素, 生产性能, 营养品质