Nitrogen is fixed by rizobium bacteria any time or at the time of lightning only. How Industry help in nitrogen fixation and when oxygen react with nitrogen to form dilute nitric acid, is it not affecting the plant ( harm to plant because it is acid)

Industrial nitrogen fixation through the Haber (or Haber-Bosch) process is a deliberate attempt of humans to produce ammonia. It requires high pressure (200 atmospheres) and temperature (400°C), and the resulting ammonia is used for agriculture as a synthetic nitrogen fertilizer to enrich land for crop growth. It is also, indirectly, relevant to the manufacture of all chemical compounds that contain nitrogen which includes most pharmaceutricals and dyes.

It is estimated that the resulting ammonia sustains 1/3 of the Earth's population. It is also estimated that 1/2 of the protein in a human consists of nitrogen originally fixed by the Haber process.

However, negative effects to the environment have also accompanied this process, as the large increase in fixed nitrogen is contaminating the surface water, groundwater, and the atmosphere - producing dangerous consequences.