Abstract: Reasonable intercropping system with forage combination is the key to improve forage quality and play the advantages of intercropping system. In this study,alfalfa (Medicago sativa) with maize (Zea mays) and sorghum (Sorghum saccharatum) (line ratio 4∶2),alfalfa with oat (Avena sativa) and triticale (Triticale Wittmack) (row ratio 4∶4) were intercropped in Lanzhou from 2016 to 2019. It was found that the crude protein content of alfalfa in different intercropping systems was decreased significantly compared to that of corresponded monoculture,the decline ranged from 7.2% to 14.1%. The crude protein content of oat and triticale was significantly higher than that of corresponded monoculture,with an average increase of 5.7% and 7.4% in 3 years,respectively. In 2018 and 2019,the acid detergent fiber content was significantly decreased by 7.6% compared to that of corresponded monoculture. The relative feed value of oat showed a significant increase of 8.7% and 8.3% in intercropping compared to that of monoculture in 2018 and 2019,respectively. In summary,intercropping systems between alfalfa and gramineae forages in Lanzhou were beneficial for improving the quality of gramineae forages,but it reducing the quality of alfalfa.

Key words: Intercropping, Forage, Nutritional quality, Feeding quality

摘要： 合理的间套作组合是改善饲草品质，发挥间套作优势的关键。本研究于2016—2019年在兰州地区对紫花苜蓿(Medicago sativa)与玉米(Zea mays)和甜高粱(Sorghum saccharatum)(行比4∶2)、紫花苜蓿与燕麦(Avena sativa)和小黑麦(Triticale Wittmack)(行比4∶4)进行间套作。研究发现，紫花苜蓿在不同间套作组合中其粗蛋白含量均较其单作均表现出极显著地下降，降幅达到7.2%~14.1%；燕麦和小黑麦在间套作下其粗蛋白含量显著高于单作，3年分别平均提高了5.7%和7.4%。2018年和2019年，燕麦在间套作下酸性洗涤含量较其单作显著降低了7.6%。燕麦的相对饲用价值在2018年和2019年时表现为间套作较其单作显著提高了8.7%和8.3%。综上，兰州地区紫花苜蓿与玉米、甜高粱、燕麦和小黑麦间套作时，有利于禾本科饲草品质的提升，但降低了紫花苜蓿的品质。

关键词: 间套作, 饲草, 营养品质, 饲用品质