Difference Between Carbon and Nitrogen Cycle

Main Difference – Carbon Cycle vs Nitrogen Cycle

Carbon cycle and nitrogen cycle are two processes that occur in ecosystems. Both processes are involved in interactions between animals and nature related things. The main difference carbon and nitrogen cycle is that carbon cycle is involved in the recycling of carbon whereas nitrogen cycle is involved in the recycling of nitrogen. Both processes have multiple ways of recycling carbon and nitrogen. Both cycles start and end with gases. Since both carbon and nitrogen cycles work simultaneously, they are often referred to as CNO cycle.

Key Areas Covered

1. What is Carbon Cycle
      – Definition, Importance, Steps of the Process
2. What is Nitrogen Cycle
      – Definition, Importance, Steps of the Process
3. What are the Similarities Between Carbon Cycle and Nitrogen Cycle
      – Outline of Common Features
4. What is the Difference Between Carbon Cycle and Nitrogen Cycle
      – Comparison of Key Differences

Key Terms: Carbon Cycle, Combustion, Fixation, Global warming, Nitrogen cycle, Photosynthesis, Protoplasmic Decay, Respiration

What is Carbon Cycle

The carbon cycle is the series of processes by which carbon dioxide is fixed by photosynthesis, forming organic nutrients and ultimately is restored by respiration, combustion, or protoplasmic decay. The source of carbon for the carbon cycle is atmospheric carbon in the form of carbon dioxide. Plants and other photosynthetic organisms fix atmospheric carbon by photosynthesis. This produces simple sugars such as glucose. Plants convert glucose into complex organic compounds such as carbohydrates, lipids, and proteins for the storage. These plants are eaten by herbivores; herbivores are eaten by carnivores. Cellular respiration occurs in all these organisms, which results in the breakdown of organic compounds.

Figure 1: Carbon Cycle

 During respiration, carbon dioxide is released into the environment as a gas. Some portion of carbon dioxide is released by the breakdown of dead organisms. The other portion of carbon dioxide remains as fossil fuels. During the combustion of these fossil fuels, the rest of the carbon dioxide is released into the atmosphere. The rapid release of carbon dioxide to the environment by human activities may cause global warming.

What is Nitrogen Cycle

The nitrogen cycle is the process by which the atmospheric nitrogen successively passes from air to the soil, to organisms, and again to the atmosphere. The atmosphere contains 78% nitrogen gas. The nitrogen fixing bacteria in the soil converts this nitrogen into ammonia, nitrite, and nitrates. These nitrogen compounds are absorbed by plants to make proteins. These proteins are consequently consumed by herbivores and carnivores. Proteins are used in making structures and as energy sources.

Figure 2: Nitrogen Cycle

The breakdown of dead organisms by nitrifying bacteria releases nitrogen compounds back to the soil. These nitrogen compounds in the soil are released to the atmosphere by denitrifying bacteria. The nitrogen cycle is shown in figure 2. 

Similarities Between Carbon Cycle and Nitrogen Cycle

• Carbon cycle and nitrogen cycle are two processes involved in recycling the materials of the ecosystems.
• Both carbon cycle and nitrogen cycle maintain interactions with animals and other nature related components in the ecosystem.
• Both carbon cycle and nitrogen cycle comprise multiple processes to complete the entire cycle.
• Both cycles start with gases and ends with gases.
• Since both carbon and nitrogen cycles work simultaneously, they are often referred to as CNO cycle.

Difference Between Carbon Cycle and Nitrogen Cycle

Definition

Carbon Cycle: Carbon cycle is a series of processes by which compounds of carbon are interconverted in ecosystems.

Nitrogen Cycle: Nitrogen cycle is the series of processes by which nitrogen and its compounds are interconverted in ecosystems.

Significance

Carbon Cycle: Carbon cycle is involved in recycling carbon in ecosystems.

Nitrogen Cycle: Nitrogen cycle is involved in recycling nitrogen in ecosystems.

Important Processes

Carbon Cycle: Photosynthesis, deposition, and decomposition are the important processes of the carbon cycle.

Nitrogen Cycle: Fixation, mineralization, nutrition, and denitrification are the important processes of the nitrogen cycle.

Start

Carbon Cycle: Carbon cycle starts with the atmospheric carbon dioxide.

Nitrogen Cycle: Nitrogen cycle starts with the atmospheric nitrogen gas.

Fixation

Carbon Cycle: Carbon fixation occurs by the photosynthesis in autotrophs.

Nitrogen Cycle: Nitrogen fixation occurs by the nitrogen fixation bacteria.

Fixing Substances

Carbon Cycle: The atmospheric carbon dioxide is converted to simple and complex sugars by plants.

Nitrogen Cycle: The atmospheric nitrogen is converted to ammonia, nitrite, and nitrates by nitrogen fixation bacteria.

Release to the Atmosphere

Carbon Cycle: The fixed carbon is released to the atmosphere by respiration, combustion, and protoplasmic decay.

Nitrogen Cycle: The fixed nitrogen is released to the atmosphere by decay and denitrification.

Interference by Humans

Carbon Cycle: The increased release of carbon dioxide to the atmosphere may cause global warming.

Nitrogen Cycle: Humans should interfere in the addition of nitrogen sources into plants.

Interference of Organisms

Carbon Cycle: Animals and plants are involved in the processes of the carbon cycle.

Nitrogen Cycle: Microorganisms are involved in the process of the nitrogen cycle.

Conclusion

Carbon cycle and nitrogen cycle are two recycling processes that occur in ecosystems. Carbon cycle is involved in the fixation of atmospheric carbon in organisms and releasing back carbon dioxide to the atmosphere. The fixation of carbon dioxide occurs by photosynthesis. The fixed carbon is then circulated through food chains and released back to the environment by respiration and decay. Combustion also releases carbon dioxide into the atmosphere. Nitrogen cycle is involved in the fixation of atmospheric nitrogen by the soil bacteria, absorption of the nitrogen compounds by plants, circulation through food chains, and release back to the atmosphere by decay. Therefore, the main difference between carbon and nitrogen cycle is the source of gas, fixation, release, and the importance of each cycle in the ecosystems.

Reference:

1.“What is The Carbon Cycle?” Tribal Energy and Environmental Information, Available here. Accessed 15 Aug. 2017.
2. Harrison, John Arthur. “The Nitrogen Cycle: Of Microbes and Men.” Visionlearning, Visionlearning, Inc., 11 Feb. 2017, Available here. Accessed 15 Aug. 2017.

Image Courtesy:

1. “Carbon-cycle-full” By Harry C – Own work  (CC BY-SA 3.0) via Commons Wikimedia 
2. “Nitrogen Cycle” By Environmental Protection Agency –  (Public Domain) via Commons Wikimedia