Sowing machine comprises a drawbar (1), and a main frame (2) on which a frame (17) for rollers (36) is arranged that is rotated about an axle point (C) by an adjusting element (18). The main frame has at least two fixing shafts (4, 5) on which blade arms (6, 7) are fixed so that they rotate about hinge points (A, B). A tensioning device (30) is fixed to the upper ends of the blade arms and at one end to the frame for the rollers below the axle point at a point (J).
