Auswirkungen reduzierter Bodenbearbeitung und Vorfrucht auf die Unkrautvegetation

Summary

The reduction of soil tillage intensity is of special interest for organic farmers. To study the influence of reduced tillage on soil properties and weed vegetation field plots were set up in 1992 on the FAM Research farm in southern Germany. From 1999 till 2002 weed vegetation was recorded including soil seed bank, plant density, number of flowering plants and biomass. Reduced tillage intensity did not influence the weed population dymamics but did influence the species composition. Elymus repens, Apera spica-venti and Poa annua were promoted by a tillage regime that omitted deep ploughing in four of seven years. The cultivation of grass/ley mixtures plays an important role in crop rotations of organic farming systems e.g. as part of the weed management. In rotation after grass/ley mixture mechanical weeding in winterwheat led to a remarkable reduction of total weed density and flowering plants. Thus the input of fresh seeds to the seedbank is reduced.