1. Present address: Institute of Applied Plant Nutrition, University of Göttingen, Carl‐Sprengel‐Weg 1, 37075, Germany
2. Institute of Plant Nutrition and Soil Science, Kiel University, Hermann‐Rodewald‐Str. 2, 24118, Kiel, Germany
3. Institute of Bio & Geoscience Agrosphere IBG 3, Forschungzentrum Jülich GmbH, Wilhelm‐Johnen‐Straße, 52428 Jülich, Germany
4. Rothamsted Research, North Wyke, Okehampton EX20 2SB, UK
5. School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth, PL4 8AA, UK
6. Department of Environmental Science, Lancaster University, Lancaster, LA1 4YQ, UK
7. UIQA Instituto Superior de Agronomia, TU Lisbon, Tapada da Ajuda, 1349‐017 Lisboa, Portugal