1. USDA/ARS — Soil Drainage Research Unit, Columbus, OH.
2. Biosystems Eng. and Soil Science Dept., Univ. of Tennessee, Knoxville, TN.
3. Dept. of Agric. and Biol. Eng., Clemson Univ., Blackville, SC.
4. Soil and Water Science Dept., Univ. of Florida, Gainesville, FL.