1. USDA-ARS; Conservation and Production Research Lab.; Bushland TX 79012
2. Dep. of Soil, Water, and Climate; Univ. of Minnesota; Southwest Research and Outreach Center; 23669 130th St. Lamberton MN 56152
3. USDA-ARS; Southern Regional Research Center; New Orleans LA 70124
4. USDA-ARS; Grassland Soil and Water Research Lab.; Temple TX 76502
5. Dep. of High Latitude Agriculture; Univ. of Alaska; Fairbanks AK 99775