The Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. (The other components of the atmosphere are trace elements and the greenhouse gases.) Nitrogen is the most abundant element in the atmosphere. For this reason, it might not seem like living organisms would find it difficult to get the nitrogen they need in order to live. But it is! This is because atmospheric N2 is not in a form that can be used directly by most organisms. Thus, while the atmosphere is the major reservoir in this cycle, a step is needed to convert that nitrogen into usable forms. Most of the other reservoirs in the nitrogen cycle hold nitrogen compounds for relatively short periods of time.🏁

The Earth's atmosphere is made up of approximately 78 percent nitrogen and 21 percent oxygen. (The other components of the atmosphere are trace elements and the greenhouse gases.) Nitrogen is the most abundant element in the atmosphere. For this reason, it might not seem like living organisms would find it difficult to get the nitrogen they need in order to live. But it is! This is because atmospheric N2 is not in a form that can be used directly by most organisms. Thus, while the atmosphere is the major reservoir in this cycle, a step is needed to convert that nitrogen into usable forms. Most of the other reservoirs in the nitrogen cycle hold nitrogen compounds for relatively short periods of time.🏁