Prairie Soils & Crops Journal Establishing a Symbiotic Relationship Between Legume Plants and Rhizobial Bacteria

Legume crops commonly grown in western Canada have the ability to form an association with a bacterial partner, called Rhizobium, and together these partners are capable of “fixing ” gaseous nitrogen into a form that is plant available. This symbiotic association is beneficial to both partners. The plant is able to access a form of nitrogen that otherwise is unavailable, and the bacteria receive a ready source of energy from the plant. This remarkable partnership between plant and bacteria is highly organized and coordinated. Indeed, the simplicity of using a commercial rhizobial inoculant to enhance nodulation and ensure adequate nitrogen fixation in commercial legume crop production belies the complexity of the partnership. An examination of the many steps leading to the establishment of a symbiotic N-fixing association helps reveal factors that can contribute to, or prevent, successful nodulation