Objective of this demonstration is to determine how much air is present in different samples of soil and to then explain its relevance.
Standards: Properties of Earth Materials (physical and chemical properties of soils).
Materials: small clear jars, water, and soil samples
(1) Fill each jar about half full with a different soil sample.
(2) Then fill each jar almost to the top with water.
Science Behind It: Depending on the individual soil samples being tested, you will see a varying amount of air bubbles rising up from the soil to the top of the water in the jar. From this, you will be able to tell the approximate amount of air trapped in the spaces between the soil particles because a larger amount of air bubbles indicates a larger amount of trapped air. This demonstration can be used to discuss the properties of different soils. Soil samples that are densely packed, like clay textured soils, have less room for air to be trapped than other samples, like organic rich soil that form air pockets. This may also be a good time to discuss how most plants prefer soils with loose structures and many air pockets over densely packed soils.