https://winrock.org/ms/fact-net/?pid=21305
Nitrogen fixing trees (NFTs) are special in their potential for agroforestry planting. Through nitrogen fixation, this critical soil nutrient is extracted from the atmosphere and converted to a form usable by plants. The trees don’t perform this process but instead this is done by symbiotic soil microorganisms which live in nodules on the trees roots. Bacteria of the genus Rhizobium inoculate leguminous NFTs, while actinomycetes (relatives of fungae) of the genus Frankia inoculate most other NFTs. The fixed nitrogen allows fast growth rates and high production of tree products. The nitrogen can also be made available to associated agricultural crops, and livestock through appropriate tree management systems.