Legumes' capacity for nitrogen fixation has several impacts. Legumes can grow in nitrogen deficient soils and at the same time produce protein-rich plant material, particularly protein rich seeds. This high protein content and production, which is intrinsic to legumes, determines much of the role of legumes not only in general human and animal nutrition, but also their suitability for novel feed uses and uses in the non-food sector.
Biological nitrogen fixation is a characteristic of pioneer plants and so gives rise to another potential use of legumes in the bioremediation or colonization of soils otherwise unsuited for agriculture. Legumes are also, compared with cereals, rich in a range of secondary plant compounds. Legumes have evolved mechanisms to produce and concentrate these compounds to protect against pest and disease attack. The bioactivity of these compounds opens up non-food opportunities which are specific to legumes.
This report also looks at non-traditional feed uses, such as whole-crop silage and fish feeds, examines some industrial uses of legumes in the bio-based economy, and concludes with a catalogue of recent demonstrations of the activities of bioactive compounds derived from legumes. A comprehensive gathering of such data would require hundreds of pages and thousands of references, and this document is intended to introduce the reader to the literature and present some of the more interesting highlights that are relevant in the context of European agriculture.