Agronomist, with a master's degree (1992) and a doctorate (1996) in Soil Sciences from the Federal Rural University of Rio de Janeiro, Brazil, and a post-doctorate (2005) in Geosciences from the University of Edinburgh, UK. Credentialed professor of the Postgraduate Program in Agronomy at the Federal Rural University of Rio de Janeiro (active teacher since 1998). Since 2015, he is a member of the Embrapa Management Committee on Climate Change and a member of the Agronomy Committee of the National Research Council (CNPq). He published more than 100 articles and several books and book chapters on biological nitrogen fixation, recycling of N and C in agricultural systems, use of stable isotopes (15N and 13C) in agriculture, and sequestration of C from soil and greenhouse gases in the agricultural systems of Brazil.