Wonders of Rhizobium 

 -  Indian Farming, p.84-86, 1981 .
<br/><br/> Nitrogen, an essential construent of protein, is present in abundance (about 80 per cent)in atmospheric air yet it is useless to the vast majority of organisms because of its inert nature. Nitrogen can enter biological systems only when it has been fixed or combined with certain other elements such as hydrogen or oxygen. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>RHIZOBIUM<br/>NITROGEN<br/>HYDROGEN<br/>OXYGEN