Richard G. Burns is Professor of Environmental Microbiology at the University of Kent, Canterbury, England. The author, coauthor, editor or coeditor of over 100 research articles, book chapters and books, he is a member of the Society for General Microbiology, the International Union of Soil Sciences, the International Association on Water Quality, and the Society of Chemical Industry. A Chief Editor of Soil Biology & Biochemistry, he received the B.Sc. degree (1966) from the University of Wales, and the Ph.D. degree (1969) from the University of London, England. Richard P. Dick is Professor of Soil Science at Oregon State University, Corvallis. The author, coauthor, editor or coeditor of over 120 journal articles, invited proceedings, book chapters and books, he is a member of the Soil Science Society of America and the International Union of Soil Sciences, among others. A Fulbright Scholar and an associate editor for the Soil Science Society of America Journal, he received the B.S. degree (1974) in plant science from the University of Minnesota, Twin Cities, the M.S. degree (1977) in soil science from Louisiana State University, Baton Rouge, and the Ph.D. degree (1985) in soil science from Iowa State University, Ames.