Nitrogen Fixation by Actinomycete-Nodulated Angiosperms

Abstract

Nitrogen fixation by symbiotic associations between soil bacteria belonging to the actinomycetes and root systems of a diversified group of woody dicotyledonous plants is less generally well known than that by the legume-Rhizobium symbiosis. The fixation of dinitrogen by nodulated legumes is a major mechanism for entry of reduced nitrogen into agricultural lands and, to a much lesser extent, to wooded ecosystems. For forested areas, woodlands, wetlands, and fields, nodulated plants like the alders (Alnus), bog plants like sweet gale (Myrica gale), and roadside and disturbed area invaders such as sweet fern