1. USDA-ARS, Agricultural Systems Research Unit, 2150 Centre Ave.; Bldg. D, Ste. 200 Fort Collins CO 80526
2. USDA-ARS, Wind Erosion and Water Conservation Research Unit; Cropping Systems Research Laboratory; 3810 4th St. Lubbock TX 79415
3. Agronomy College, Qingdao Agricultural University; Changcheng Rd. 700, Chengyang District Qingdao Shandong China 266108
4. USDA-ARS, Central Plains Resources Management Research Unit; 40335 County Rd. GG Akron CO 80720-0400
5. CSIRO Land and Water, Christian Laboratory; Clunies Ross St., Black Mountain ACT 2601 Australia
6. USDA-ARS, Conservation and Production Research Lab.; P.O. Drawer 10, 2300 Experiment Station Rd. Bushland TX 79012-0010