Provides a clean furrow edge. Serrated, or also smooth, 500 mm diameter coulter discs with taper roller bearing. From choice, two carrier arms in different lengths for the optimum positioning to the plough body and skimmer. The short carrier positions the disc to the side of the skimmer and thus provides a clean last furrow. With the long carrier, the coulter disc runs in front of the skimmer and thus provides the optimum clearance and thus reduces the danger of blockage.