1. Biological and Agricultural Engineering Dep.Univ. of Arkansas203 Engineering HallFayettevilleAR72701
2. USDA–ARS National Soil Erosion Research Lab., 275 South Russell StreetPurdue Univ.West LafayetteIN47907
3. Crop, Soil, and Environmental Sciences Dep.Univ. of Arkansas115 Plant SciencesFayettevilleAR72701