g23.    What are some characteristics of soil?

There are many grades of soil.

1. Clay is very fine particles (like chalk dust).
2. Silt is slightly larger particles.
3. Sand is medium sized particles.
4. Gravel is coarse sized particles.
5. A mixture of clay, sand, silt and humus is a loam.
6. Soil porosity is the amount of pores or spaces in the soil.
7. Soil permeability is the rate at which water or air move through the soil.  

e19.    What materials can cause water pollution?

e23.    How is soil important to plants?

m01.    How much public land is there and how is it used?

m06.    How can rangelands be responsibly managed?

m17.   What’s happening to the tropical forests?

m41.    How can matter affect the environment?

m56.    How can we increase mineral resource supplies?

m74.    How is soil important in the environment? 

m75.    How can soil be conserved? 

m76.    What contaminates soil?