Don't Wash That Dirt Away
by Mary Salmon Kennedy
“Aw, Mom,” a boy groans. He doesn't want a bath. His sister pouts when told to wash her dirty hands. Would everyone be happy if there were no dirt? Not farmers. They couldn't plant their corn. Not earthworms. They couldn't dig their holes.
An earthworm's home, and the dirt around it, can be called a factory. This factory makes a special kind of dirt called topsoil.
Millipedes, spiders, and many other tiny insects live in a worm's home. It's like an insect highway. We might call the walls plain old dirt, but they are really tiny bits of stone piled one on another. The pieces of rock are held together by a kind of cement called humus. It is made of dead and decayed bodies of plants and tiny animals.
Small plants such as fungi and algae supply food for the hungry travelers. Fungi are the kind of plants that grow on moldy bread. Algae grow in damp places. When the roots of plants die, they leave paths for water. Air also comes down the same pathways.
As the water trickles down, it washes the sides of the tiny stones. It washes over the humus and gathers minerals. This is called soil solution. It is full of the nutrients that plants need.
The soil solution, humus, and tiny rocks combine to make topsoil. Without topsoil, there could be no plants. Without plants, there could be no animals on land. Without topsoil, Earth would be an almost lifeless globe revolving in space.
- What is soil solution?
[anno: Soil solution is water that has trickled down through the topsoil and picked up minerals and other nutrients as it passes over stones and through humus.]
- Why is topsoil important? Write a few sentences explaining your answer.
[anno: Topsoil is important because it is rich in nutrients. Without topsoil, plants would not be able to grow. The topsoil provides air and minerals for plant roots, and it helps capture water for the plant roots.]
- When an earthworm digs a hole into the ground, it leaves behind a tiny tunnel. How do you think earthworms help plants to grow? Write a sentence or two for your answer.
[anno: The tunnels left behind by earthworms are important for helping plants grow because the tunnels allow air and water to get into the soil. The plants need this air and water to grow.]