Soil thermal resistivity refers to the ability of the soil to absorb and transfer heat in different environments. Thermal resistivity influences the ability of the soil to transfer energy between various soil particles as well as the surrounding space. You may be wondering why this transfer potential is important. Indeed, thermal resistivity has multiple implications in agriculture, engineering and environmental planning.
For example, if a particular type of soil retains heat over long periods of time, it will affect the ability of engineers to install underground cables and other types of infrastructure. Soil with low thermal resistivity (retains heat well) may cause underground equipment to easily overheat and require regular cooling.
There are certain factors that influence the thermal resistivity of soil. Some of these include:
As the environmental temperature increases, the thermal resistivity of any soil sample will decrease. This is because heat causes individual soil particles to vibrate with higher frequencies and as a result, transfer heat to neighbouring objects.
However, the individual characteristics of the soil sample will determine how likely the soil is to absorb and transfer heat. Soil particles that have smaller surface areas are less likely to absorb heat and transfer it in the process. Such soils have a high thermal resistivity and provide a more stable environment for engineering applications.
On the other hand, soils with small particles may not be the best candidates for farming. Along with their high resistivity, they are also unable to retain nutrients and provide a fertile medium for crops to grow.
The structure of the soil also influences its thermal resistivity. Structure refers to the general arrangement of soil particles in the environment. Tightly packed and evenly arranged particles are more likely to absorb, retain and transfer heat. On the other hand, randomly arranged and spaced out soil particles are less efficient in heat absorption and retention (think of it in terms of why solids are better heat conductors than gases).
Well-arranged soils therefore have low thermal resistivity and tend to retain heat better. This makes them unsuitable for underground engineering applications but excellent for agricultural purposes. The proper arrangement of particles provides a stable environment for crop growth.
Testing and measurement methods
Proper testing and measurement of soil samples will determine their thermal resistivity readings as well as their suitability for various applications. You will find that the thermal resistivity of soils will vary depending on their moisture levels and the state of the outside environment.
For example, clay soils have a lower thermal resistivity when they are wet (they retain more heat in this case) and a higher thermal resistivity when dry (due to the randomly arranged particles). Therefore, the conditions under which measurements are taken should be carefully considered.
Contact a company that offers soil thermal resistivity testing to learn more.Share