A hub-bearing assembly serves to rotatably mount a soil-working disc (D) on a supporting axle (A) of an agricultural machine. The assembly comprises a hub-bearing unit (10) and a sealing device (20). The a hub-bearing unit has a radially outer, rotatable outer race (11) from one side of which a flange (12) radially extends for mounting a disc (D). The sealing device (20) is mounted on a side of the hub-bearing unit opposite to the side of the flange (12). The radially outer surface of the assembly has a portion (38) intermediate the flange (12) and the side of the sealing device (20), which isradially recessed so as to serve as a preferential seat for winding wires picked up from the fields during use of the agricultural machine.