The expert-derived assessment of selected diseases and weeds showed that the presence of legumes in arable cropping systems did not systematically change the infestation risk at the cropping system scale (not shown). In forage systems in Brandenburg, a set of data was selected to systematically compare grass–clover and alfalfa with silage maize systems on soil type 3 (Fig. 6, A). Systems with grass–clover had no infestation risk for couch grass (score of+/− 0.4) and take-all (score of 0.3 to −0.6). Systems with silage maize had an infestation risk for couch grass (score of 0.2–1.5) but not for take-all (score of 0.4 to −0.8). In Västra Götaland (Fig. 6B),grass–clover based systems had a lower infestation risk for take-all (score of −0.1 to −1) than temporary grassland (score of -0.1 to0.6). The couch-grass infestation risks were similar in both systems(score of 0.2–1).