How is dirt made? And why do we need it?
Soil is the top layer of the ground. It can be several feet deep or only a few inches. Rain, snow, ice, and sun break big rocks into tiny rocks. As leaves fall, twigs and branches break, and bugs die they mix with the rocks and create dirt. This process does not happen overnight, sometimes it can take thousands of years.
The air and water in dirt gives plants important nutrients to grow and animals who live underground food and air to survive.
We also need soil to grow our food and flowers. Did you know that dirt also protects the air we breathe and the temperature of the earth? Scientists have discovered important medicines like penicillin from dirt and artists use pigments from the crushed rocks in their paint.
What can’t dirt do?
- It can take 100-500 years to make only 1 inch of dirt
- Soils can come in all different colors
- Just one spoonful of soil holds billions of creatures you can only see in a microscope
- Plant roots help dirt from eroding or blowing away
- Lava from volcanoes cools and becomes a hard rock and over time the rain and wind break down the rock into tiny pieces and it becomes soil
Is All Soil the Same? Down & Dirty: The Secrets of Soil by Ellen Lawrence
Step-by-Step Experiments with Soils by Gina Hagler