In the nitrogen cycle, phytoplankton and other marine plants turn nitrate (NO3) into organic nitrogen during photosynthesis. The organic nitrogen sinks into the deep ocean, where microbes "eat ...

These human activities convert nitrogen from inactive to reactive forms. “Before the Haber-Bosch process and fossil fuel combustion, specialized microbes in the soil could fix nitrogen into forms ...

The nitrogen cycle was a foundation of life on Earth, ... Banner image: A farmer uses nitrogen and phosphorus fertilizers. Image by CityofGeneva via Flickr (CC BY-NC 2.0).

As the world’s population grows and releases more nitrogen, the hidden parts of its cycle may come painfully to light. [Image via Wikipedia ] Click here to go to the full Science Tattoo Emporium.