By means of a schematic diagram show how a bacteria cell applied to the region of a cowpea root can end up by becoming a nitrate ion which can be absorb by a subsequent crop.

Nitrifying bacterium such as nitrosomonas or nitrobacter, whe applied to the soil, convert free ammonia or nitrogen to nitrates through oxidation. They are a group of aerobic bacteria playing an important role in the nitrogen cycle as producers of energy from inorganic source.

The schematic diagram attached summaries the action of such bacteria.