An agricultural machine (10) for cleaning soils used to grow orchards or vineyards, comprising a frame (11) configured to be connected to a tractor, a power connector (12) fixed to said frame (11) and configured to be connected to a power taking-off of the tractor, a rotor shaft (13) fixed to the frame (11) in a rotatable manner with respect to a transverse axis of rotation and provided with a series of cutters (33), and a transmission unit (14) fixed to the frame (11) and connected both to the power connector (12) and to a middle portion of the rotor shaft (13) to operate it. A pair of telescopic guides (17) are connected to related telescopic portions (15) mounted above the rotor shaft (13) in correspondence of respective portions (31, 32) of the rotor shaft (13). Each of said portions (31, 32) has a first end fixed at the transmission unit (14) and a second end fixed at a side plate (16), so that the side plates (16) are able to translate in order to compact or enlarge the working area of the cutters (33).
