Legume

Legumes are pods or fruits of the Fabales order of plants. They include beans, peas, peanuts, alfalfa, soybeans, and vetch. Legumes are important because of their use in human and animal feed and because of the various products they yield, including fibers, edible oils, and plastics. Consequently, industries based on legumes are significant in terms not just of providing nutrition, but also of creating inputs into other economic activities. The current value of legumes is estimated at around two billion dollars annually, with many more used as local food sources and not included in official statistics. Since legumes are of particular importance in improving land quality, the use of legumes is likely to intensify in the future as population growth, climate change, environmental degradation, and desertification decrease [Page 1039]the amount of exploitable and productive land per capita.

Legumes yield many important products, including fibers, edible oils, and plastics.

Legumes are of importance for their ability to fix atmospheric nitrogen and for the symbiotic relationship they can maintain with rhizobia, which means they are particularly useful in crop rotation schemes to prevent nitrogen depletion in the soil. This also enables legume growers to reduce the amount of artificial fertilizer used to grow plants. The high nitrogen content is also associated with the high level of protein within legumes. Some manufacturers produce rhizobia for use as seed inoculants on a commercial basis.

The rhizobia-legume symbiotic system can fix as much as 300 pounds per acre in the right circumstances. This process means that legume-rhizobia combinations can be of great assistance in promoting sustainable agriculture in areas that previously have not been very fertile. Several thousands of tons of cereal and legume seeds were dispatched to Eritrea, for example, to try to improve the fertility of the land in the wake of the drought of 2002. The necessity of inoculating the legumes is recognized by the Food and Agricultural Organization of the United Nations.

However, the use of genetically modified (GM) rhizobia is more controversial and it is clear that in many countries significant proportions of the population are opposed to any form of GM food. Any use of GM seeds that would contaminate non-GM food, and must be labeled as such, would be resented and rejected by significant numbers of consumers. There is also the risk that GM legumes would have unanticipated impacts on the soil and on surrounding flora and fauna.