Science
What is The nitrogen cycle?
The nitrogen cycle is how nitrogen moves through the air, soil, and living things. Bacteria convert nitrogen gas into forms plants can use; animals get it by eating plants; and it eventually returns to the air — keeping life supplied with this essential element.
See it, don’t just read it.
Watch a 2-minute lesson with voice + animation that explains the nitrogen cycle.
Key things to understand
- 1Nitrogen cycles between air, soil, and organisms.
- 2Bacteria 'fix' nitrogen gas into usable forms.
- 3Plants absorb it; animals get it by eating plants.
- 4Decomposition and other bacteria return it to the air.
Frequently asked questions
- What is the nitrogen cycle?
- The natural movement of nitrogen through the atmosphere, soil, and living organisms.
- Why is the nitrogen cycle important?
- Nitrogen is essential for proteins and DNA, and the cycle keeps it available to living things.
- What is nitrogen fixation?
- The process where bacteria convert nitrogen gas into compounds plants can absorb and use.