Soil for grade 3

1. SOIL
HOW DOES SOIL AFFECT
LIVING THINGS?

2. Why is soil important?
SOIL provides support and nutrients
for plant growth to give us…
• Medicine
• Food
• Cotton to make clothes
• Wood

3. Weathering
breaks down rocks to create soil.
It can be caused by weather,
water, or living things
How was soil formed?
It takes
thousands of
years

4. There are three components of soil:
1. Weathered Rocks rocks broken into small pieces by weather
2. Minerals
3. Humus from the remains of dead plants and animals
• Soil is a mixture of

5. Humus
Humus is made of leaves, twigs, small
animals, or other decayed substances.
Humus adds many nutrients to the soil.
Humus is in the dark in color.

6. 3 Layers of Soil
1. Topsoil (The layer on TOP)
2. Subsoil (The prefix SUB means under)
3. Bedrock (It’s hard as rock down there!)

7. Humus and minerals gives
the topsoil a rich brown
color.
Lighter color with less
humus and minerals.
Mostly rocks.
Also called Solid Rock