[1]Institute of Animal Sciences;
Chinese Academy of Agricultural Sciences;
Beijing 100193;
P.R. China;
[2]Institute of Grassland Science;
College of Animal Science and Technology;
China Agricultural University;
Beijing 100193;
P. R. China;
[3]Department of Crop and Soil Science;
Oregon State University;
Corvallis 97331;
USA;
紫花苜蓿; 无芒雀麦; 混合物; 施氮量; 生长; 产量; 温室; 氮含量;