Student Features

What's the Scoop on Soil?
06.23.09
 
A cartoon of three children studying the dirt in a hole dug in a forest

Some animals, like earthworms, live in the soil. Credit: Lisa Gardiner/UCAR

It's easy to forget about soil. You have to look down on the ground to see it. Even then, soil may not seem to do very much. But there's more to soil than you might think. It isn't just dirt that gets on your shoes.

Trees and plants need soil to grow. Very few fruits, vegetables and grains would live without it. Many animals need soil, too. They eat the plants that grow in it. Some animals even live in the soil. Can you imagine a world without soil?

Most soil comes from rocks. Over many years, weather causes rocks to break apart. The pieces get smaller and smaller as time goes on. Soil forms when bits of rock mix with things like dead leaves and dead bugs.

A comparison of red dirt from Arizona and black dirt from Texas

The soil in Arizona, on the left, looks different from the soil from Texas, on the right. Credit: GLOBE

Not all soil is the same. Soil comes in many colors. Some soil looks and feels different than other soil. The color and feel of soil often changes as you dig deeper into the ground. You can learn a lot by seeing and touching soil. In a way, soil is like a secret decoder.

The color of soil can sometimes tell you where you are. For example, red soil can be found in Arizona. Grey soil can be found in Nevada. Black soil can be found in Texas. Water also affects the color of soil. Wet soil is usually darker than dry soil.

The feel of soil can tell you about its ingredients. Soil contains different amounts of sand, silt and clay. Soil in a forest might be gritty, which means more sand. Soil in a meadow might be smooth, which means more silt. Soil in a garden might be sticky, which means more clay.

Did you know that squeezing soil can tell you about the weather? If soil crumbles between your fingers, then the weather has probably been dry. If soil is wet and sticky -- yuck! -- then it might have rained not too long ago.

A cartoon of three children studying the dirt in a hole dug in a grassy area

Looking closely at soil can tell you about the weather. Credit: Lisa Gardiner/UCAR

Soil that is wet and sticky is called mud. Some people don't like to get mud on them. But if someone offers you mud pie, you might first want to find out how it was made. Some mud pies are made by playing with water and soil. But the dessert called mud pie is actually made of chocolate! Yum!

To read a storybook about soils, click on the first link in the gray box. To learn songs about soils, visit the second link in the grey box.

Related Resources
Elementary GLOBE: The Scoop on Soils   →
Soil Songs   →


 
 
Dan Stillman, Institute for Global Environmental Strategies