Biological Fixation 
The capturing of atmospheric Nitrogen by rhizobium bacteria which are present in roots nodules of legume plants (the Family is now classed as Fabaceae, previously Leguminosae) such as white clover.
Biological Fixation
The capturing of atmospheric Nitrogen by rhizobium bacteria which are present in roots nodules of legume plants (the Family is now classed as Fabaceae, previously Leguminosae) such as white clover.