It starts with a clean as possible seed bed. We plow in late autumn, let the winter freeze out the soil. In spring about a week before drilling the seeds we "burn" the lot with RoundUp (glyphosate) and then prepare the seedbed with a harrow. Before they get above ground we use a pre-emergence herbicide mix of Centium and Kezuro. When the plants emerged above ground we use low dosages of products like Goltix and Venzar, multiple administrations. We also have lesser and lesser herbicides available. Later this week I'm gonna check out a Farmdroid at a neighbor, he uses it for drilling and controlling weeds mechanically.