Hanna Poffenbarger, Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY, US, Cynthia A. Cambardella, USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA, Matt Liebman, Department of Agronomy, Iowa State University, Ames, IA, Antonio P. Mallarino, 716 Farm House Lane, Iowa State University, Ames, IA, US, Daniel C. Olk, 1015 N. University Blvd., USDA-ARS National Laboratory for Agriculture and the Environment, Ames, IA, US, Ann E. Russell, Iowa State University, Ames, IA, Johan Six, Department of Environmental Systems Science, ETH, Zurich, Switzerland and Michael J. Castellano, Iowa State University, Ames, IA, US