Nitrogen fixing actinomycetes: Frankia for nodulation in non-legumes
Biotechnological methods are also being developed, which will help non-leguminous plants (other than conventional crops) to survive under conditions of adverse nutrient supply. There are about 160 species of angiosperms, which are known to form nitrogen fixing root nodules with the actinomycetes bacteria belonging to the genus Frankia which has become a subject of intensive studies in recent years.

Frankia helps in nitrogen fixation in non-leguminous plant species and therefore can be used for land reclamation through reforestation due to high biomass production without the need of expensive nitrogen fertilizers. Of these non-legume nitrogen fixing systems, alder trees (Alnus spp.) have been found to supply 12-300 kg N ha-I yr-l, through leaf fall, excretion from roots, and nodule decays.