Ammonia (NH3) can be products by bacteria in the soil by two processes:

What. And. What

Biologically: Nitrogen gas (N2) diffuses into the soil from the atmosphere, and species of bacteria convert this nitrogen to ammonium ions (NH4+), which can be used by plants ... Through lightning: Lightning converts atmospheric nitrogen into ammoniaand nitrate (NO3) that enter soil with rainfall.

Answer: Ammonification and nitrogen fixation.

Explanation:

Ammonification is the process where by organic nitrogen is converted ammonia in the soil by bacteria. These occur when bacteria breakdown the remains of dead plants and animals to release organic nitrogen and it is converted to ammonia.

Nitrogen fixation it is the process where atmospheric nitrogen is converted to ammonia or nitrate in the soil, in a way it is absorbed by plants. It is fixed by bacteria in root nodules of leguminous plants or by lightening.