​Symbiotic nitrogen-fixing microorganisms

Symbiotic nitrogen-fixing microorganisms can fix molecular nitrogen in the air only when they are mutually beneficial with plants. Symbiotic nitrogen-fixing microorganisms can be divided into two categories: one is Rhizobium, which is mutually beneficial with legumes, and the other is Actinomyces frankii, which is symbiotic with non-legumes such as alder, bayberry, and sea buckthorn; Cyanobacteria symbiotic with aquatic ferns such as Hongping (also known as Manjianghong) or gymnosperms such as Lohan pine.