In Washed Away, learn how erosion -- when soil is washed away by wind or water -- occurs. Because soil is a mixture of inorganic and organic materials, the ratio of these elements determines how well the soil can support plants and withstand erosion. Watch what happens when you cause erosion to occur.
What You'll Need:
- Three aluminum-foil cooking pans
- Three lengths of rubber or plastic tubing (1/2-inch in diameter)
- A mixture of soil, sand, and clay
- Potting soil
- Blocks of wood
- Three bowls
- Cereal grains
- Plant mister
- Watering can
Step 1: Poke a small hole in one end of each aluminum pan, near the upper rim.
Step 2: Put one end of a length of tubing into each hole, using tape to hold it there.
Step 3: Into each pan put a layer of the soil, sand, and clay mixture.
Step 4: Add a layer of potting soil on top of that.
Step 5: Put all three pans indoors in a place where they will get sunlight.
Step 6: Rest all three pans on blocks of wood to elevate the pans at about a 30-degree angle. The tubing should be on the bottom end of each pan. Put the free end of each tube into a bowl.
Step 7: In one pan, make rows across the width of the pan and plant cereal grains in the rows.
Step 8: In another pan, make the rows lengthwise and plant the grain. Don't plant anything in the third pan.
Use a plant mister to keep the grain moist until it sprouts. Continue to water the grain until the seedlings are about two inches tall. Don't do anything to the empty pan. Once the seedlings in the two pans are about two inches tall, begin using a watering can to sprinkle all three pans. The watering can should have a spout that imitates rain. Each time you water the pans, watch the water that runs into the bowls.
Which bowl collects more potting soil? Why? What could you do to prevent potting soil from eroding into the bowls?
Go to the next page of science projects for kids: density and volume to learn how difficult it can be to undo pollution.