Legumes in agriculture

Last changed: 26 March 2011

There are more than 18 000 species of legumes in the world, mainly trees and shrubs in tropical and subtropical areas, but also herbs ranging all the way to arctic areas. A great majority of legumes (for example clover, lucerne, pea and bean) have a fascinating biology in their ability to form root nodule symbioses with nitrogen-fixing bacteria, rhizobia, making them largely independent of soil nitrogen availability. Cultivated legumes are known to be able to supply many services to mankind, notably:

•protein-rich foods and feeds and N-rich green-manures,
•biologically fixed dinitrogen (N2) to the legume host, and via legume residues and animal manure to the soil for the benefit of the entire agro-ecosystem,
•building of soil fertility via C and N sequestration,
•biofuels, fuelwood,  pharmaceuticals, industrial chemicals,
•diversification of crop rotations and reduction in the requirement for pesticides,
•potential to reduce fossil energy requirement and emissions of greenhouse gases in production systems,
•prevention of soil erosion by strip intercropping

Historically, legumes have been integrated components of cropping systems worldwide, but following agricultural industrialization legumes have disappeared from many agricultural systems, despite their many useful services. Education, interdisciplinary research, innovation and synthesis of existing knowledge as well as improved dissemination are required to improve the reintegration of legumes in food systems in Sweden and globally.