Read ST pp.188-195
AM pp.137-138
What is soil?
Is all soil the same?
What makes up most of soil?
What other things are in soil?
What is humus?
How does humus help plants?
. What are the three main sizes of soil?
What are the smallest particles of soil made of?
What are the largest particles made of?
What are the three layers of soil?
Does the soil in each layer look the same?
What does topsoil contain that gives it a dark color?
What does topsoil contain that gives it a dark color?
| 
