Rattan Lal, PhD, is a professor of soil physics in the School of Natural Resources and director of the Carbon Management and Sequestration Center, FAES/OARDC at Ohio State University.Carlos C. Cerri, PhD, is a professor at the Centro de Energia Nuclear na Agricultura of the Universidade de São Paulo, Brazil, where he teaches graduate students and performs research on soil carbon sequestration and trace gas mitigation on tropical conditions. Martial Bernoux, PhD, is research soil scientist at the French Institut de Recherche pour le Développement (IRD) since 1999, now member of research unit "Soil carbon sequestration and soil bio-functioning." Jorge Etchevers, PhD, is a professor of soil science at the Colegio de Postgraduados, Mexico, and a permanent visiting professor of the Universidad of Concepción, Chile. Eduardo Cerri, PhD, is a post-doc at the Centro de Energia Nuclear na Agricultura (CENA-USP), Brazil. In 2003 he received his PhD in soil science from the University of Sao Paulo.