What Is Mud?



This lesson developed by Reach Out!
Recommended Age: Preschool and Early Elementary


Questions

What is mud?
How do puddles form?



What You Need

  1. Large plastic tub (like a dishwashing tub)
  2. Bag of potting soil or a bucket of gardening dirt
  3. Pitcher of water



What You Do

  1. Fill your plastic tub about 1/2 full with soil.
  2. With the palm of your hand, press down a few places in the soil to make some dents or holes where water can go to make puddles.
  3. Carefully sprinkle or drip water from the pitcher onto your soil. Keep going untill the soil has abosrbed or taken all the water it can into itself.
  4. Then add some more water.



What Is Happening

Your soil can take in and hold certain amounts of water. When it is what we called "saturated," it just can't hold any more water. Then the water starts to stand on top of the soil. Where we pressed down on the soil, we made little pockets where the wa ter could collect and stand on top of the soil. These are like puddles we see after a rainstorm. Think about how the soil looked when it was dry and then how it looks after it absorbs water. Its texture and feel is very different.

You can try this again but this time mix your dry potting soil with gravel or with clay. See what happens when you add water. There are different kinds of soil. Some, like clay, will not absorb water very well. Gravel and stones definitely don't take in much water. What kind of soil do we want around our houses? Why? Where have you seen flooding and mud puddles after a rain? Why?