1. Dept. of Soil, Environ. and Atmospheric Sci.; Univ. of Missouri; 302 ABNR Building Columbia MO 65211
2. USDA-ARS; Cropping Systems and Water Quality Unit; 302 ABNR Building Columbia MO 65211
3. Dept. of Soil, Environ. and Atmospheric Sci.; University of Missouri; 302 ABNR Building Columbia MO 65211