**Acknowledgements**

The authors wish to heartily acknowledge the support under the BG05M2OP001-1.002-0019 *Clean technologies for sustainable environment – waters, waste, energy for the circular economy* **"***(Clean&Circle)* Project financed by the Operational program "Science and Education for Smart Growth" 2014-2020, cofinanced by the European Union through the European structural and investment funds.

*Phosphorus in Soils and Plants*
