The impact of biochar dosing with simultaneous fertilization with a biogas plant digestate on the volumetric density of soilJakub Sikora, Urszula Sadowska, Agnieszka Klimek-Kopyra and Maciej GliniakE3S Web Conf., 132 (2019) 02006DOI: https://doi.org/10.1051/e3sconf/201913202006