1. USDA-ARS, Soil Drainage Research Unit; 590 Woody Hayes Dr. Columbus OH 43210
2. Univ. of Waterloo; Dep. of Geography and Environmental Management; 200 University Ave. W. Waterloo ON N2L 3G1 Canada
3. Purdue Univ.; Dep. of Agricultural and Biological Engineering; 225 S. University St. West Lafayette IN 47907
4. USDA-ARS, Grassland, Soil and Water Research Lab.; 808 E. Blackland Rd. Temple TX 76502
5. USDA-ARS, Pasture System and Watershed Management Research Unit; Bldg. 3702, Curtin Rd. University Park PA 16802
6. Ohio State Univ.; Dep. of Food, Agricultural, and Biological Engineering; 590 Woody Hayes Dr. Columbus OH 43210