(introduction...)

Soil is a mixture.

Get a little earth from a valley, from a plateau and from the side of a slope.
Put the earth from each field in a different glass. (If you haven't got glasses, use empty bottles.)

Earth from first and second field

· In each glass or bottle put two fingers of earth.
Fill up with water.

· Stir the mixture well in each glass.
Put it down and do not touch it for Jive minutes.

· Stir the mixture well in each glass once more.
Put it down and do not touch it for an hour.

An hour later, what do we see?

The earth has dropped to the bottom of the glass and the water is clear.

Look at the earth: several layers have formed.

· At the bottom of the glass there is a layer of sand and some little pebbles.

· In the middle is a layer of silt.

· Above is a thin layer of clay.
If the water is not clear, that is because clay is still mixed with the water.

· On top of the water float pieces of leaves and roots. The leaves and roots rot and form humus.

Thus the soil is a mixture.