1. Biological Sciences Department, Rabigh‐College of Science and Arts, King Abdulaziz University, PO Box 344, Rabigh 21911, Saudi Arabia
2. Soils and Water Use Department, Agricultural and Biological Division, National Research Centre, 33 Al Behoos St., P. O. Box 12622, Dokki, Cairo, Egypt
3. Soils Department, Faculty of Agriculture, Mansoura University, Mansoura, Egypt