hcho15.html

There's a huge hill near Kinetic City that we like to ride our bikes down. hill

It's so popular, we've worn a big, clear path through the woods.

bike
When it's dry, it gets kind of dusty -- but we still have a blast.

But when it rains... yuk! What a mess!
mudboy

I noticed last time it rained that the path of the hill that has trees and grass and stuff doesn't get so messy. But the trail we ride on gets all gouged out and muddy.

It's like a big scar on the ground. Seems like the trees and bushes hold the soil in place and stop it from washing away!

Hey, Home Crew, do your own sliding soil experiment!


	A shoe box
	Aluminum foil
	4 cups of soil
	2 huge handfuls of dried leaves and twigs
	2 cups of water

	Line the inside of the shoe box with aluminum foil. Now wrap the lid of the box in foil. Place the lid in the box on a slant to make a ramp.

	All of the soil should be slightly damp for this experiment. If it isn't, add water to it. Take half of the soil and spread it out to cover the ramp.
	Take the other half of the soil, and mix in all of the crunched-up leaves and small sticks that you've collected. Put that soil aside for a few minutes.
	Take 1 cup of water and pour it along the top edge of the ramp as slowly as you can.
*What happens to the soil as you pour the water?* *What do you predict will happen when you try this with the other soil?*
	Now, clear away all of the plain soil, and spread the soil with stuff in it over the ramp.
	Again, pour out 1 cup of water exactly as you did in the first soil test, as slowly as you can along the top of the ramp.
*What happens to the soil as you pour water on it?* *Is there a difference between the types of soil?*

When soil gets washed away by water and wind, it's called erosion. Things that are mixed in with the soil help prevent erosion. What kinds of things?

Well, leaves and sticks worked for your experiment, but roots work even better. The roots of trees and even grass are like underground nets that keep soil from washing away. They also absorb water and nutrients from the soil and hold soil particles together.

Soil erosion is bad because when soil gets washed away, so do valuable nutrients!