Switzerland ' s livestock production causes high environmental costs and depends strongly on feed imports. While plant-based protein demand increases, the local grain legume production is negligible ( similar to 9000 hectares). Here, we investigated the potential of sustainable legume protein production based on an expert survey followed by a quantitative analysis based on yield, soil, terrain and climate data. Pea, soybean and faba bean showed high potential for Swiss agriculture given adaptions in policy, pricing and breeding. The potential grain legume production area was 107,734 hectares on suitable arable land (Scenario I). Switzerland's self-sufficiency could be increased by cutting imports and maximizing legume production on 181,479 hectares (Scenario II) in expense of grassland and fodder maize. This would replace approximately 41% of animal protein consumption with plant-based protein, preserving 32% of milk and 24% of meat protein. In conclusion, domestic legume production could be substantially increased while improving human and environmental health.
