DEM simulation research of selected sowing unit elements used in a mechanical seeding drillJacek Marcinkiewicz, Jarosław Selech, Żaneta Staszak, Łukasz Gierz, Dariusz Ulbrich and Dawid RomekMATEC Web Conf., 254 (2019) 02021DOI: https://doi.org/10.1051/matecconf/201925402021