1. Soil and Water Department; Faculty of Agriculture, Sebha University; PO Box 19332 Sebha Libya
2. School of Agriculture, Food and Rural Development, Newcastle University; Newcastle upon Tyne NE1 7RU UK
3. School of Civil Engineering and Geosciences, Newcastle University; Newcastle upon Tyne NE1 7RU UK
4. School of Chemical Engineering and Advanced Materials, Newcastle University; Newcastle upon Tyne NE1 7RU UK