1. USDA-ARS Water Management and Systems Research Unit; 2150 Center Ave., NRRC Building D Fort Collins CO 80526
2. USDA-ARS, Soil Management and Sugar Beet Research Unit; 2150 Center Ave., NRRC Building D Fort Collins CO 80526
3. Dep. of Soil and Crop Sciences; Colorado State Univ.; Fort Collins CO 80523