Thomas J. Sauer, USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA, US, Elizabeth M. Heatherington, Environmental Science and Education, Chemeketa Community College, Salem, OR, Matthew B. Duesterhaus, Department of Agronomy, Iowa State Agronomy Club, Ames, IA and Cynthia A. Cambardella, USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA