Steven B Mirsky, Bldg. 001, Rm 011, 10300 Baltimore Avenue, Beltsville, MD, US, Victoria J. Ackroyd, 10300 Baltimore Ave, University of Maryland, College Park, MD, US, Stephane Cordeau, Agroecology lab, INRA, Dijon Cedex, France, William S. Curran, 116 AG Science and Industry Building, Pennsylvania State University, University Park, PA, Masoud Hashemi, Stockbridge School of Agriculture, University of Massachusetts-Amherst, Amherst, MA, US, S Chris Reberg-Horton, Crop and Soil Science, North Carolina State University, Raleigh, NC, Matthew Ryan, Cornell University, Ithaca, NY and John T. Spargo, Tower Road, Ag Analytical Services Lab, University Park, PA