Several bacteria like Rhizobium and blue-green algae take up free atmospheric nitrogen and convert it into ammonia that combines with organic acids to form amino acids. This process is called biological nitrogen fixation. During lightning, the high temperatures and pressures created in the air convert nitrogen into oxides of nitrogen. These oxides dissolve in water to give nitric and nitrous acids and fall on land along with rain. These are then utilised by different life- forms. The chemical fertiliser factories produce ammonia by combining hydrogen and atmospheric nitrogen under high pressure and temperature. This process is called industrial nitrogen fixation.

The conversion of atmospheric nitrogen into nitrates and nitrites, which are then utilized by plants and animals, is a process known as nitrogen fixation.
There are techniques for fixing nitrogen, including industrial operations and lightning.
Because it is needed in the production of proteins, nitrogen is crucial for the existence of life.
Rhizobium, industrial processes, and lightning are all capable of nitrogen fixation.
A commercial procedure called the Haber's process is used to fix nitrogen.
Ammonia is created during this process by converting nitrogen.
Water, natural gas, which provides hydrogen, and iron, which serves as the catalyst are the basic ingredients needed for catalysis. Air provides nitrogen.
Rhizobium can also fix nitrogen. They transform it into inorganic nitrogen. After that, it is converted into amino acids, which plants use.
Lightning can fixate nitrogen as well. In this process, the atmosphere's nitrogen and oxygen combine to generate oxides of nitrogen.
These gases create weak nitric acid when they interact with rainwater. The soil mineral reacts with these traces of nitric acid to create nitrates.

Nitrogen fixation by industries, Rhizobium, and lightning

Industries:
- Industries can fix nitrogen through the Haber-Bosch process, which converts atmospheric nitrogen into ammonia. This ammonia is used to produce fertilizers and other nitrogen-rich products.

Rhizobium:
- Rhizobium is a genus of nitrogen-fixing bacteria that forms a symbiotic relationship with leguminous plants. These bacteria convert atmospheric nitrogen into a form that plants can use for growth, thus improving soil fertility.

Lightning:
- Lightning also plays a role in nitrogen fixation by converting atmospheric nitrogen gas into nitrogen oxides, which then dissolve in rainwater to form nitrates. These nitrates are deposited in the soil, providing a source of nitrogen for plant growth.

All of the above:
- All three sources mentioned (industries, Rhizobium, and lightning) contribute to nitrogen fixation in different ways. Industries provide a human-made method of nitrogen fixation, Rhizobium bacteria form symbiotic relationships with plants for nitrogen fixation, and lightning naturally converts atmospheric nitrogen into usable forms for plants. Together, these sources help maintain nitrogen levels in the soil and support plant growth and ecosystem health.