g24.    How does soil move?

Erosion is the movement of soil from one place to another. Soil is moved primarily by either wind or water. Tropical and temperature areas take 200 to 1,000 years to regenerate 1 inch of topsoil. Erosion is milder on forested or rangeland than or cropland; regeneration takes 2 to 3 times longer in forests.  

e19.    What materials can cause water pollution?

e23.    How is soil important to plants?

m17.   What’s happening to the tropical forests?

m74.    How is soil important in the environment? 

m75.    How can soil be conserved? 

m76.    What contaminates soil? 

m78.    How do droughts and floods impact populations?