Where do Animals get Nitrogen from?

We all know that plants and animals both require oxygen to stay alive. However, did you ever even think that they might need some other gases apart from oxygen as well? Well, the answer to this question is yes, animals do require other gases apart from oxygen like nitrogen to survive. Where do animals get nitrogen from, how do animals get their nitrogen, how do plants get nitrogen and the nitrogen cycle are some of the things that we will discuss here. So let’s get started.

1. Why do Animals and Plants need Nitrogen?

Proteins, vitamins, and hormones are some of the crucial things that both plants and animals require to function properly.

• Lack of protein in animals can result in Fatty liver, stunted growth, swelling, and much more. However, even plants cannot function without protein because it is related to photosynthesis, biosynthesis, and immunity. (See What are the End Products of Photosynthesis?)
• The lack of vitamins in animals leads to reduced productivity, and they become prone to more diseases. Chlorosis, mottling, and bronzing of younger leaves are some of the problems that plants face when they lack vitamins.
• Hormones are important for animals because they help in regulating important functions of the body like growth, hunger, reproduction, etc. On the other hand, a lack of hormones in plants results in aging, flowering, and root growth defects.

Since all these essential things are present in nitrogen itself, it is important that plants and animals both receive a good amount of nitrogen.

2. Where is Nitrogen found? Where do Animals get Nitrogen from?

Nitrogen is basically a non-metallic element that is present in group 15 of the periodic table. Since nitrogen is the most prevalent gas that is required for human, animal, and plant survival, we should know what it looks like and where it is found. However, it is a colorless, odorless, and tasteless gas.

Nitrogen gas is found everywhere in the Earth’s atmosphere. About 4/5 of the Earth’s atmosphere consists of nitrogen gas. The nitrogen gas stands sixth in the cosmic abundance among the elements. Where do animals get nitrogen from? Since nitrogen gas is available in abundance and is present everywhere around us, we can say that animals also get nitrogen gas from the air around us. Furthermore, as we do not practice selective breathing by breathing in just oxygen, nitrogen also finds a way to get inside the animals’ bodies, by the process of absorption. (See How do Animals cause Erosion?)

3. How do Animals get their Nitrogen?

Well, animals do not breathe in nitrogen. So, where do animals get nitrogen from? They have a different way of consuming nitrogen for the proper functioning of their body. After they consume a plant or other animals, they absorb the nitrogen that was present in the plants or dead animals. However, it is important for plants to consume nitrogen first, and only then animals can absorb it. (See What are Examples of Living Things?)

4. How do Plants get Nitrogen?

If plants do not get enough nitrogen, animals will automatically suffer. This is because animals get their nitrogen from eating plants. However, the question remains how do plants get nitrogen? Basically, the roots of the plant absorb nitrogen from the soil and water which is available to them. Since plants cannot move from one place to another, they can only make use of the limited amount of nitrogen that is present around them. Nitrogen-fixing bacteria and blue-green algae help in fixing the nitrogen and convert the nitrogen which gets into the soil, and is ultimately absorbed by the plants. (See What are Few Examples of Producers Consumers and Decomposers?)

5. How does Nitrogen get into the Soil?

The nitrogen cycle helps the plants to absorb nitrogen first before getting absorbed by the animals. It is a biological, geological, and chemical mechanism through which nitrogen is changed into a variety of forms before returning to the atmosphere after first entering the soil and then organisms. There are five stages in the nitrogen cycle that you must go through to get an idea of where do animals get nitrogen from. They are:

• Nitrogen fixation process: This is the first step of the nitrogen cycle where nitrogen present in the atmosphere is converted into usable nitrogen so that it becomes available for plants and animals to make use of it. It is converted from N₂ to NH₃. There are three types of nitrogen fixations like atmospheric fixation, industrial nitrogen fixation, and biological nitrogen fixation. Must read How are Elements and Compounds Similar and Different?
• Nitrification: The next step is nitrification. Since there are bacteria in the soil, the ammonia is changed into nitrate in this process. Nitrosomonas is a bacterial species that helps in the oxidation of ammonia throughout the process. The reaction involves is:

2NH₃ + 3O₂ → 2NO₂^‾ + 2H⁺ + 2H₂O

2NO₂^¯ + O₂ → 2NO₃^‾

• Assimilation: Ammonia, nitrite ions, nitrate ions, or ammonium ions help in the protein formation for the plants and is absorbed from the soil. Since plants are the primary consumers, they consume this nitrogen and pass it on to animals in the food web.
• Ammonification: Now is the time to wonder about what happens when plants and animals die. Once they die, after decomposition, the nitrogen is again broken down into its original form and is returned to the soil. This nitrogen is used in many biological processes.
• Denitrification: When nitrogen makes its way back into the atmosphere, that stage is known as the denitrification phase. (See What are the Uses of Soil?)

6. How does Nitrogen get back into the Atmosphere?

Earlier we read how nitrogen gets into the soil and where do animals get nitrogen from, now it’s time to learn how it gets back into the atmosphere. When nitrate is converted back into nitrogen gas, bioavailable nitrogen is removed and returned back to the atmosphere. This process of nitrogen getting back into the atmosphere is known as Denitrification. The end product of the process of denitrification is the dinitrogen gas. However, this is not the only gas that is formed.Denitrification returns nitrate back into its original form which is nitrogen gas and that is how it gets back into the atmosphere. (See What is Sustainability and Why is it Important?)

7. How do Animals contribute Nitrogen to the Nitrogen Cycle?

Besides, where do animals get nitrogen from, animals contributing nitrogen to the nitrogen cycle is a very interesting topic. Let us now understand what actually goes on. We all know that animals do not get nitrogen directly from the atmosphere. The nitrogen cycle takes place, and nitrogen is supposed to be absorbed by the plants before it gets to the animals. This is because when the nitrogen gas is converted into nitrate, it is present in the soil. To absorb nitrate from the soil, the plants need to absorb it through the roots. Once the plant absorbs the nitrate, it gets eaten by an animal. The animal that consumes the plant receives the nitrogen. 

However, once these plants and animals die and start decomposing, this nitrate is again converted into nitrogen gas and is released back into the atmosphere. This is how animals contribute nitrogen to the nitrogen cycle.

We hope that all your questions like where do animals get nitrogen from, how do animals get their nitrogen, how do plants get nitrogen, and what is nitrogen cycle are cleared by now. It is important to be aware of what is going on in your surroundings to stay updated and understand how it is relevant to your life. (Also read Where do Buffaloes roam?)