Mikolaj Piniewski¹, Paweł Marcinkowski¹, Joanna O'Keeffe¹, Mateusz Szcześniak¹, Anna Nieróbca², Jerzy Kozyra², Zbigniew W. Kundzewicz³ and Tomasz Okruszko¹, (1)Warsaw University of Life Sciences, Warszawa, Poland, (2)Institute of Soil Science and Plant Cultivation - State Research Institute, Puławy, Poland, (3)Institute for Agricultural and Forest Environment, Polish Academy of Sciences, Poznan, Poland