Sustainable increase in the self-sufficiency of Swiss agriculture – the potential of grain legumes in a traditionally meat- and dairy-based production

Switzerland is a global hotspot in dairy production and has above-average values of per-capita meat consumption. Its livestock production causes high environmental costs and is highly depending on concentrated feed imports. At the same time, the local grain legume production is negligible and diets of Swiss population become more and more plant-based. The consumption of legume protein has two main advantages over meat protein: legume-based protein has a lower environmental footprint due to biological nitrogen fixation and it has a healthy composition. This study evaluates the potential of grain legumes to diversify agricultural products while increasing sustainable food production and self-sufficiency. Especially peas and faba beans show potential for the Swiss agriculture but require adaptions in policy, pricing and breeding based on a qualitative assessment of expert opinions. A quantitative analysis using Geographic Information system (GIS) showed that when only suitable arable land (Scenario I) is used for grain legume production, more than 100% of Switzerland's meat protein consumption could be covered by legume-based proteins. Converting suitable meadows into additional arable land for legume production (Scenario II) would further increase this potential: 180% of the currently consumed meat protein could be generated. The increase in legume area could be compensated by forage area, i.e., leys and silage maize. Replacing 632,500 t of concentrated feed import additionally, the current monogastric and ruminant production would decrase by 31 and 39%, respectively. The ramped up production of legume protein (175,630 t) could replace the decrease in animal-based proteins (from milk and meat) and substantially increase self-sufficiency of Swiss agriculture. Increasing legume production is one promising path for Swiss agriculture toward more sustainability allowing to decrease environmental costs, such as greenhouse gas (GHG) emissions, nitrogen pollution, and pressure on deforestation through soybean import. To stimulate legume production, not only policy needs to increase support, but also the supply chain of the agricultural and food industry are to be built up in parallel. Besides that, the agricultural management of legume production needs to be improved and new varieties adapted to current and future requirements are to be developed.