Nancy Carlson  age 10 of Bridgeport, Conn

 Does an inch of topsoil take a, thousand years?

Top soil is a mixture of powdered rocks and chemicals moistened with rain or snow. Long ages were necessary to chomp up the solid rocks. Seasons of heat and frost made them expand and shrink and forced them to crack. Wind and water worked to dissolve and break boulders into fragments, dust and dirt.

The chemicals were added to the dirt by generations of plants and animals. As they died, their tissues were rotted and decayed. This job was done by tiny molds and bacteria. When it was done, the organic matter of old plants and animals was broken down into simple chemicals. Rain water fell to dissolve them so that new plants could use them as food.

In some places the old earth cannot make an inch of top soil in a million years. The climate may be too dry or too severe. In other places, an inch of rich top soil can be made in a hundred years.