<p>From the composition of soil air, we know that oxygen is much less than that of atmospheric air. On the other hand, carbon dioxide is higher in soil. However, nitrogen gas is very much similar in both cases. According to the chapter <em>Aeration</em> in the book <em>Encyclopedia of Soils in the Environment (2005)</em>,</p>
<blockquote>
<p>Since nitrogen gas (N<sub>2</sub>) is more abundant than other gases in the atmosphere (approx. 78%) and there are generally no sources or sinks for N<sub>2</sub> in the soil (except N<sub>2</sub> absorbed during nitrogen fixation or produced during denitrification), the concentration of N<sub>2</sub> in the soil air will be similar to that in the atmosphere, varying only slightly depending on the production and consumption of other soil gases.</p>
</blockquote>
<p>Is there a better explanation? Is this the only reason for the similarity? An explanation with references will be appreciated.</p>

CC BY-SA 4.0
2021-06-04T14:39:39.943Z
what is confusing, things in the soil respire turning O2 in to CO2 the same is not true of nitrogen.
John
CC BY-SA 4.0
2021-06-04T15:10:45.573Z
Yes, the nitrogen is not getting used, but is this the only reason? Any other physiochemical parameters responsible for this?
Padmanabha
<soil-science><nitrogen><air>
Why is the concentration of nitrogen gas almost equal in soil air and the atmosphere?
Padmanabha
# Why is the concentration of nitrogen gas almost equal in soil air and the atmosphere?

(Asked by: username_0 on 2021-06-04)

From the composition of soil air, we know that oxygen is much less than that of atmospheric air. On the other hand, carbon dioxide is higher in soil. However, nitrogen gas is very much similar in both cases. According to the chapter *Aeration* in the book *Encyclopedia of Soils in the Environment (2005)*,

> Since nitrogen gas (N2) is more abundant than other gases in the atmosphere (approx. 78%) and there are generally no sources or sinks for N2 in the soil (except N2 absorbed during nitrogen fixation or produced during denitrification), the concentration of N2 in the soil air will be similar to that in the atmosphere, varying only slightly depending on the production and consumption of other soil gases.

Is there a better explanation? Is this the only reason for the similarity? An explanation with references will be appreciated.

**Tags:** soil-science, nitrogen, air

> **Comments:**
> **username_1**: what is confusing, things in the soil respire turning O2 in to CO2 the same is not true of nitrogen.  
> **username_0**: Yes, the nitrogen is not getting used, but is this the only reason? Any other physiochemical parameters responsible for this?  

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## 0 answers

