1. Institute for Plant Nutrition, Leibniz University of Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
2. Present address: Soil Science and Plant Nutrition Department, Faculty of Agriculture, University of Erciyes , 38039 Kayseri, Turkey
3. Present address: Soil and Water Science Department, Faculty of Agriculture, University of Alexandria, El‐Shatby, 21545 Alexandria, Egypt
4. Present address: Agricultural Analysis and Research Institute (LUFA), Obere Langgasse 40, 67346 Speyer, Germany