1. Department of Environment and Agronomy, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA, CSIC), 28040 Madrid, Spain
2. Environmental Engineering Department, Engineering Faculty, Mersin University, Mersin 33100, Turkey
3. Department of Electronic Engineering, Hellenic Mediterranean University, 73100 Chania, Greece
4. Laboratory of Soil Science and Agricultural Chemistry, Agricultural University of Athens, 11855 Athens, Greece