Other than bacteria, which factor leads to nitrogen fixation

Nitrogen is very important for plants growth. Nitrogen fixation is the process by which atmospheric nitrogen is assimilated into organic compounds especially by microbes. Nitrogen fixation can be carried out by bacteria and lighting. The vast amount of energy in lightening decompose nitrogen molecules and enables the nitrogen atoms to combine with oxygen in the air forming nitrogen oxides. These oxides dissolve in the rain to form nitrates which are carried into the soil. The percentage of nitrogen fixed by this method is between 5%- 8% of all nitrogen fixed.