1. Research Assoc., Agricultural Engrg., Univ. of Idaho Research and Extension Center, Kimberly, Idaho 83341
2. Prof., Agricultural and Civ. Engrg., Univ. of Idaho Research and Extension Center, Kimberly, Idaho 83341
3. Supervisory Soil Sci., U.S. Dept. of Agr.‐Agricultural Research Service, Snake River Conservation Research Center, Kimberly, Idaho 83341