terrestrial ecosystems
Nitrogen Fixation: Root and Bacteria Interactions Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. Atmospheric nitrogen, which is the diatomic molecule N2, or dinitrogen, is the largest pool of nitrogen in terrestrial ecosystems. However, plants cannot take advantage of this nitrogen because they do not have the necessary enzymes to convert it into biologically useful forms. However, nitrogen can be fixed, which means that it can be converted to ammonia NH3 through biological, physical, or chemical processes. As you have learned, biological nitrogen fixation BNF is the conversion of atmospheric nitrogen N2 into ammonia NH3 , exclusively carried out by prokaryotes such as soil bacteria or cyanobacteria. Biological processes contribute 65 percent of the nitrogen used in agriculture. The following equation represents the process:.