1. Dep. of Soil and Atmospheric Sciences; Univ. of Missouri-Columbia; 302 Anheuser-Busch Natural Resources Building Columbia MO 65211
2. USDA-ARS, Univ. of Missouri, Columbia; Columbia MO 65211
3. Dep. of Biological Engineering; Univ. of Missouri, Columbia; 269 Agricultural Engineering Building Columbia MO 65211