1. International Institute for Water and Environmental Engineering (2iE), Ouagadougou Campus, Rue de la Science, 01 BP 594 Ouagadougou, Burkina Faso
2. University of Brasilia, Brasilia , Distrito Federal CEP 70910-900, Brazil
3. French Agriculture Research Centre for International Development (CIRAD), 73 Rue J. F. Breton, 34398 Cedex 5 Montpellier, France