On farm research is well established in organic farming. The holistic approach considers the complexity of a farm and the findings will be implemented immediately. As the experiments are often performed on single farms the results are difficult to transfer to others. Controlled experiments on group level with representative samples investigate single factors and lead to reliable and well-founded results. However, they are often far away from implementation. Applied research requires interplay of on farm research and controlled experiments. A series of ethological research work should show how this interplay may take place