西藏林芝河谷地带紫花苜蓿和高羊茅混播牧草品质研究

为了探究西藏林芝河谷地带紫花苜蓿（Medicago sativa L.）与高羊茅（Festuca elata Keng ex E.Alexeev）混播对草地产量和牧草品质的影响，以单播为对照，采用随机区组设计，测定了不同茬次牧草的生产性能和营养指标。结果表明：混播干草产量分别达14 917.05 kg·hm^-2，13 288.82 kg·hm^-2和8 729.86 kg·hm^-2，显著高于单播产量。牧草混播第1至3茬的粗蛋白质含量分别为14.07%，13.62%和20.50%，显著高于单播高羊茅，低于单播紫花苜蓿；平均粗脂肪含量达2.24%，显著高于单播处理。牧草干重与粗纤维含量呈极显著正相关，与粗脂肪含量呈显著正相关关系，与粗蛋白质含量呈显著负相关关系。不同处理（茬次）灰色关联度综合评价排序结果为A3>B3>C1>A1>A2>B2>B1>C2>C3。2种牧草混播具有一定的优势，可在林芝河谷地带广泛栽培推广和利用。

Study on Forage Quality of Mixed Planting Medicago sativa L. and Festuca elata Keng ex E. Alexeev in Nyingchi Valley,Tibet

In order to explore the effects of mixed sowing of Medicago sativa L. and Festuca elata Keng ex E. Alexeev on grassland yield and forage quality in Nyingchi Valley of Tibet. Using single sowing as control,the production performance and nutritional indexes of different stubble times were measured by random block design. The results showed that the species mixtures significantly increased hay the yield with 14 917.05 kg·hm^-2,13 288.82 kg·hm^-2,and 8 729.86 kg·hm^-2 in different plant species mixtures,respectively. The crude protein contents were 14.07%,13.62%,and 20.50% at the first to the third harvest in mixed cropping of forage grass,respectively. Single sowing of Medicago sativa L. has higher crude protein content than that of Festuca elata Keng ex E. Alexeev. Moreover,species mixtures significantly increased crude fat content. The dry weight of herbage positively correlated with crude fiber content and crude fat content,but negatively correlated with crude protein content. The degree of high-quality forage in different treatments ranked A3>B3>C1>A1>A2>B2>B1>C2>C3. Our finding highlights that the plant mixtures have pronounced advantages in forage yield,which should be widely promoted and used in Tibet valley regions.