There are serious sustainability issues with South American soy production, due largely to the rapid increase in soy acreage triggered by a marked rise in global demand. One of the main applications of soy is in the form of soybean meal for animal feed. A possible solution to the cited issues might therefore be to replace the soy-based feed used in Europe today with feed produced from home-grown ingredients. There are several leguminous crops eligible for this purpose, in particular peas, field beans and lupins.
To assess whether substitution of soy by European grain legumes would be a wise move requires thorough analyses of sustainability aspects. This report presents recommendations for guidelines for such analyses. These relate to two issues: assessment of sustainability as such, and comparative assessment of soy versus legumes. It is proposed to adopt a ‘stacked’ approach comprising both sustainability criteria and LCA. In comparative LCA studies the definition of the system boundaries and the choice of impact categories are of pivotal importance for the results obtained.