1. USDA-ARSForage and Range Res. Lab.Utah State Univ. Logan UT 84322-6300
2. USDA-ARSNorthwest Irrigation and Soils Res. Lab. 3793 N 3600 E Kimberly ID 83341
3. Agric and Agri-Food CanadaSemiarid Prairie Agric. Res. Center P.O. Box 1030 Swift Current SK Canada S9H 3X2
4. USDA-ARSNorthern Great Plains Res. Lab. P.O. Box 459 Mandan ND 58554