The Nitrogen Cycle
Nitrogen is the most abundant element in our planet’s atmosphere. Approximately 78% of the atmosphere is comprised of this important element.
Nitrogen is used by lifeforms to carry out many of the functions of life. This element is especially important to plant life. Yet, nitrogen in its gaseous form is almost entirely unusable to lifeforms. It must first be converted or ‘fixed’ into a more usable form. The process of converting nitrogen is called fixation.
There are specialized bacteria whose function it is to fix nitrogen, converting it, so that it can be used by plants. There are still other bacteria who do the reverse. That is, they return nitrogen to is gaseous form.
After nitrogen is fixed, it can be absorbed and used by plants, and subsequently by animals.
The process of nitrogen being fixed, used by plants and animals, and later returned to the atmosphere is referred to as the nitrogen cycle.