Soil sedimentation test

Mix soil with water, and let it settle, to analyse the components of different soil types.
Science content
Biology: Food Webs, Ecosystems, Biomes (3, 4)
Earth/Space: Rock cycle, Earth Materials, Natural resources (5)
Lessons activity is in
  • different soil types (e.g. forest, park, beach)
  • screw cap tubes e.g. 50ml conical lab tubes

Students add a spoon of soil to a tube, then fill the tube 3/4 of the way up with water. Shake, then let it settle.
A few seconds of settling gives some instant generalized results, and settling over a longer time gives more detailed results.

Organic matter/dead living things float.
Tiny clay particles ('mineral' component) are suspended in the water column.
Heavier sand and gravel particles ('mineral' components) sink to the bottom of the tube or jar.

Discuss the relative amounts of different components in the different soil types.
For the soil types we tested:
forest soil is almost all organic
beach soil is a mix of organic and mineral components although by volume the mineral component is larger
garden soil is a mix of organic and mineral components, with a lot of tiny mineral particles suspended in the water.

If this activity is done in a larger mason or jam jar, and left to settle over days, the mineral layers of clay, sand and gravel separate out more clearly, and their relative heights can be measured for an accurate breakdown of the mineral (rock) components of the soil.
See the image at…
and "Soil texture jar test' at

Grades taught
Gr 2
Gr 3