What is the Difference Between Soil Air and Atmospheric Air?

The main differences between soil air and atmospheric air are their compositions and locations. Here are the key differences:

• Composition: Soil air has a higher concentration of carbon dioxide (CO2) and a lower concentration of oxygen (O2) compared to atmospheric air. Atmospheric air has a high content of oxygen and a low content of carbon dioxide.
• Location: Soil air occurs in the soil pores, while atmospheric air occurs above the Earth's surface.
• Humidity: Soil air generally maintains nearly 100% humidity, unless very dry.
• Aeration: Soil aeration is essential for the proper growth of plant roots and soil organisms, as they require an appropriate amount of oxygen. Compaction or surface/sub-surface smearing can reduce the available pore space, leading to anaerobic and toxic conditions.

The exchange of atmospheric air and soil air is called "soil aeration," which occurs through diffusion, rainfall, irrigation, and wind. Maintaining a well-aerated root zone is crucial for optimum plant growth and preventing anaerobic conditions.

Comparative Table: Soil Air vs Atmospheric Air

The main differences between soil air and atmospheric air are their compositions and locations. Here is a table summarizing the differences:

Soil air is the gaseous phase found in soil, while atmospheric air is the layer of gases that occurs around the Earth's surface. Soil air has a higher concentration of CO2 and a lower concentration of O2 compared to atmospheric air. Additionally, the pressure of water vapor in soil air is close to 100%, while the nitrogen concentration is about the same in both soil and atmospheric air.