1. School of Natural Resources, 302 Anheuser‐Busch Natural Resources Building, Univ. of MissouriColumbiaMO65211
2. USDA–ARSCropping Systems and Water Quality Research Unit269 Agricultural Engineering BuildingColumbiaMO65211
3. USGSMissouri Cooperative Fish and Wildlife Research UnitColumbiaMO65211
4. Water Sciences Lab.Univ. of NebraskaLincolnNE68583