Everything needs nitrogen to live properly. Nitrogen is used to make proteins that help your muscles to grow and become stronger. Well, if it is that important, then how do we get it?
The Nitrification Cycle
Nitrogen is a chemical in the air, where it is in gas form. Every breath you take is 80% nitrogen, but our bodies cannot use nitrogen in gas form.
The nitrogen seeps into the soil, where little nodules of bacteria on plants' roots absorb it and then turn it into ammonia.
However, plants can't use this ammonia either, so it gets released into the soil again, where it gets turned into nitrites by bacteria.
Plants still can't use the nitrites, so other bacteria in the soil turns the nitrites into nitrates, which the plants can use.
The nitrates are then used by plants to help them grow, so we can get these nitrates by eating plants, which is one reason why it's critical to eat your veggies!
But how do carnivorous animals get nitrates? Carnivorous animals get nitrates by eating herbivorous animals.
After an animal dies, decomposers decompose the nitrates into nitrogen that floats back into the air, so the cycle repeats.
In short, the nitrogen cycle starts in the air. Next, it goes into the ground, where it eventually gets turned into nitrates. These nitrates are absorbed by plants, which are then eaten by animals or humans. After the animals die, they are decomposed and the nitrogen goes back into the air.