Introduction experiment of American smith elytrigia, intermediate wheatgrassand tall wheatgrass in Lanzhou, Gansu

American smith elytrigia, intermediate wheatgrass and tall wheatgrass were the xeric forage cultivars introduced from the United States in 2001. The regional test and cultivar comparison test in the semiarid regions from 2002 to 2004 were finished. The results indicated that three cultivars could adapt to the local climate conditions, and performed drought tolerance, cold resistant, high grass yield and low cost management. The fresh grass yield was ranged from 173.4 to 226.7 kg/hm2, which was 13% to 47.8% higher than the control. And the seed yield was ranged from 3.4 to 4.6 kg/hm2, which was 13.2% to 35.8% lower than the control.