The invention relates to a device (1) for crushing roots (20) in a container (18) comprising a shaft (2) arranged to be rotated around a rotation axis (3) by driving a driving end (4). The device also comprises a rotor (6) arranged at a driven end (5) of the shaft (2) and arranged to crush material when rotating. The device further comprises a shield (8) delimiting a shielded space (22) around the shaft (2), the shield (8) comprising an opening with an area (21) facing away from the driving end (4), the shielded space (22) being further delimited by the area (21) of the opening.The shield (8) is arranged to be moved along the direction of the rotation axis (3) over a range of positions comprising an operational position wherein the rotor (6) is at least partially further away from the driving end (4) than the area (21).
