The Use of Legumes for Agro-Energy and Non-Food Purposes

Summary

The vision of a more “bio-based economy” will mitigate global climate change by substituting fossil resources for energy and industrial raw materials by sustainable biomass resources, potentially refined to high value chemicals, materials and fuels in biorefinery concepts. Legume-based cropping systems can play a significant role for such paradigm shift, also when taking into account a potential adoption of less meat-intensive diets. The aim of this review is to evaluate the current knowledge and potential of legume use for agro-energy and other non-food purposes.
Legumes contribute protein rich food and feed but also many other interesting compounds, which can be refined for pharmaceuticals, surfactants or food additives (e.g. saponins, isoflavonoids, proteins). For bioenergy uses soybean and Pongamia pinnata for biodiesel is an option, like alfalfa for bioethanol, grass-clover for biogas and several tree legumes for fuel wood.
Legume-based systems are characterized by lower emissions of green-house gases caused by less dependence on fossil energy-based fertilizer nitrogen via N2-fixation combined with their cropping system diversification effects reducing pests, diseases and weed problems. On top of that legumes may contribute to carbon sequestration in soils. The possibility of including more legumes in cropping systems either as sole crops or intercropped will also be discussed.