1. ΕL.G.A., Nafplioou & Soutsou, Tripoli, Greece
2. School of Science and Technology, Hellenic Open University, Patras, Greece
3. Department of Geology, University of Patra, Rio, Greece
4. Department of Greenhouse Crops and Floriculture, Technological Educational Institute of Kalamata, Kalamata, Greece
5. Department of Soil Science of Athens, Hellenic Agricultural Organization-”DEMETER”, Institute of Soil and Water Resources, Lykovrisi, Attiki, Greece
6. Department of Soil Science of Thessaloniki, Hellenic Agricultural Organization-”DEMETER”, Institute of Soil and Water Resources, Thessaloniki, Greece