1. Dep. of Biology and Environ; Science Westminster College; 501 Westminster Ave. Fulton MO 65251
2. Dep. of Soil, Environ. and Atmos. Sci.; Univ. of Missouri; 302 ABNR Bldg. Columbia MO 65211
3. USDA-ARS; Land Management and Water Conservation Unit; Washington State Univ.; 231 Johnson Hall Pullman WA 99164
4. USDA-ARS; Cropping Systems and Water Quality Unit; Univ. of Missouri; 302 ABNR Bldg. Columbia MO 65211
5. Water Resources Research Center Dep. of Soil Water and Environ. Sci.; Univ. of Arizona; 350 N. Campbell Ave. Tucson AZ 85719
6. USDA-ARS; U.S. Arid-Land Agric. Research Center; 21881 N. Cardon Lane Maricopa AZ 85138