nitrogen cycle diagram

The nitrogen cycle describes how nitrogen moves through the environment. It begins when bacteria convert nitrogen gas from the air into forms like ammonium or nitrate, which plants can absorb. Plants take up these nutrients to grow, and animals eat the plants. When plants and animals die, decomposers break down their bodies, releasing nitrogen back into the soil. Some bacteria convert nitrogen compounds back into gas, releasing it into the air, completing the cycle. This process keeps nitrogen available for living things and maintains balance in ecosystems.