1. Soil Science Department, Faculty of Sciences, University of A Coruña (UDC), 15008 A Coruña, Spain
2. Center for Soils and Environmental Resources, Agronomic Institute of Campinas (IAC), Avenida Barão de Itapura 1481, 13022902 Campinas, SP, Brazil
3. Applied Mathematics Department, Polytechnical University of Madrid, Ciudad Universitaria, s/n, 28040 Madrid, Spain
4. CEIGRAM, Polytechnical University of Madrid, Ciudad Universitaria, s/n, 28040 Madrid, Spain
5. Department of Environmental Sciences, Xi’an Jiaotong-Liverpool University, Suzhou, Jiangsu 25123, China