1. USDA-ARS, National Soil Erosion Research Lab.; 275 S. Russell St. West Lafayette IN 47906
2. USDA-ARS, Soil Drainage Research Unit; 590 Woody Hayes Drive Columbus OH 43210
3. National Center for Water Quality Research; Heidelberg Univ.; 310 E. Market St. Tiffin OH 44883-2462
4. Dep. of Crop, Soil and Environmental Sciences, 115 Plant Science Bldg; Univ. of Arkansas; Fayetteville AR 72701