PROMISE will investigate pea-barley and lentil-pea species mixtures aiming to optimise the mixed crop systems and promote legume cultivation in Switzerland. The focus is on grain and protein yield, spread of diseases, pests and associated flora, N supply for the subsequent crop and the accumulation of pathogens in the legume crop rotation. Special attention is given to the symptoms of soil fatigue in pea and lentil. Different idiotypes of pea and lentil will be tested in field experiments in order to reach broadly based and scientifically sound conclusions. The goal is to reduce rotation breaks of legumes by optimising the selection of mixing partners. PROMISE will test novel non-destructive methods and assessments tools on organic farms in close cooperation with farmers and cantonal organic consultants. Successful combinations will be validated in demonstration trials, discussed with the farmers and published in bioaktuell and scientific journals.