There are more nitrogen gases than oxygen gases in the air. Every living things on the earth need nitrogen to grow and repair. Despite, it is impossible to use these nitrogen by breathing. We gain nitrogen by eating and plants absorb nitrogen as nitrates. This is because nitrogens are slightly lighter than water or air so they tend to stay in the form of stable gases. If any one of these living things die, nitrogens are returned back to the soil and air by decomposers like bacteria and fungi. These decomposers are very important. They break down all the dead materials and releases essential elements and compounds (like nitrogen and carbon) back to it’s cycle.
Nitrogen cycle
