1. CRETUS, Departamento de Edafoloxía e Química Agrícola, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
2. Departamento de Agroquímica y Medio Ambiente, Universidad Miguel Hernández de Elche, 03202 Elche, Spain
3. Soil Biogeochemistry, Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Von–Seckendor–Platz 3, D-06120 Halle, Germany
4. Faculty of Infrastructure and Environment, Czestochowa University of Technology, 42-200 Czestochowa, Poland
5. Faculty of Environmental Sciences and Natural Resources Management, Norwegian University of Life Sciences, P.O. Box 5003, 1433 Ås, Norway