Nitrogen fixation 'off switch' discovery could one day help crops make their own fertilizer‎

Nitrogen is essential for life. It's needed to build proteins, DNA and many other components of cells. Although nitrogen gas makes up almost 80% of Earth's atmosphere, most organisms cannot use it directly. Certain microbes solve this problem through a process called nitrogen fixation, which converts nitrogen gas into ammonia. This process is carried out by an enzyme called nitrogenase.