K-12 Education

All clays are not alike - Each of these clays has a different water holding capacity and a different shrink swell potential.  Bentonite absorbs more water than Kaolinite.  3 tablespoons of each clay was added to a cup of water.  Note that the bentonite has absorbed all the water and is stuck in the bottom of the blender while the kaolinite readily poured from the blender.  The petri dishes were filled with a thin paste of clay and water.  When the water evaporates note the amount of clay that remains in each dish. <<large picture (PDF) >>

Soils have a charge - A blue (+) charge solution was poured through the first column, and orange (-) charge solution poured through the middle column and a purple mixture is poured through the third column. Note the color of the solution passing through the first column and determine the charge of the soil. <<large picture (PDF) >>

Soil Texture Affects: Water holding capacity vs. Filtration and percolation

Soils have a charge - the charge originates in the clay and organic matter. Note on which pole the clay has accumulated. What is the charge of the soil? <<large picture (PDF) >>

Soils act as a chromatograph column - Just as this filter paper and water separate the black ink into yellow, red and blue, the soils allows chemicals to move at different rates within a profile. <<large picture (PDF) >>