Nitrogen Fixation: Root and Bacteria Interactions. Nitrogen is an important macronutrient because it is part of nucleic acids and proteins. ... The most important source of BNF is the symbiotic interaction between soil bacteria and legume plants, including many crops important to humans.
Plants I believe need nitrogen which is a chemicals to make the process called photosynthesis. Plants then release oxygen which is an element that humans breathe in.
