Stepless adjustment of the Exact harrow via spindles. The centralised adjustment of the Roller harrow is carried out via the adjusters with overload safety device. In this way, the intensity of the pressure on the rollers on the Roller harrow can be adjusted to suit soil conditions or the press rollers can be taken out of work altogether. So, the press rollers can, for instance during late autumn sowing in wet conditions, be lifted out completely. Via a series of holes, the depth of the drag tine harrow can be fine-tuned.