Nitrogen Cycle

I teach a small home school Biology class. Yesterday, we covered the nitrogen cycle. Many people assume our air is made of mostly oxygen since that is what we breathe. The actuality is though that it is mostly nitrogen. Our air is made up of about 21% oxygen, 78% nitrogen and then some carbon dioxide (0.03%) and argon (0.93%). Nitrogen is very important to life on earth as living things need nitrogen to perform the very functions of obtaining energy for themselves.

Nitrogen from the air is hard to obtain. As I told my students, it is very stingy about who it will mix with and how easily it will do it. Nitrogen fixing bacteria in our soil take the nitrogen out of the air and convert it to chemicals that like to more easily react with things. These chemicals are then used by plants and other photosynthetic organisms for energy. We then eat them to get nitrogen from them. Some nitrogen is returned to the soil naturally from our and other living things waste products. Most of the nitrogen is returned though to the air to start the process all over when they die and decomposing bacteria break them down.

In order to help my students understand this cycle more, I found this animation on the computer that explains it a little better. The only thing I do not like about it is that it shows a sprayer which would normally be associated with conventional fertilizer. Conventional fertilizer are unnecessary if we treat our soil properly in the first place but otherwise it does a good job of explaining it.  Nitrogen Cycle Animation

Learning about the how the natural process works helps us grow better gardens. Hope you will take a few minutes to learn about the nitrogen cycle.