Welcome to Science 11/21/11

1
Welcome to Science 11/21/11

• Open your book to page 255 and get your
  notes out for Ch. 10.
• Todays Schedule
• Review Sections 1 2
• Question of the Day
• Note/Discussion Ch. 10 Section 3
• Work on Weathering and Soil Formation Packets

2
Question of the Day

• What is the worlds most important natural
  resource?
• soil

3
What is soil?

• Soil- is the loose, weathered material on Earths
  surface in which plants can grow.

4
Where does soil come from?

• Bedrock- one of the main ingredients of soil.
  Solid layer of rock beneath the soil.

5
What is soil made of?

• Soil is a mixture or rock particles, minerals,
  decayed organic material, water, and air.

6
What is soil made of?

• Humus- dark colored substance that forms as plant
  and animal remains decay.

7
HUMUS

Weathering
Which is really good soil !!!!!!!!!
8
When you have really good soil it is fertile.

• Fertility- a measure of how well the soil
  supports plant growth

9
Soil Texture

• Loam- soil that is made up of equal parts of clay
  sand, and silt.

10
How is soil made?

• Soil forms as rock is broken down by weathering
  and mixes with other materials on the surface.
  Soil is constantly being formed wherever bedrock
  is exposed.

11
How is soil made?

• Soil Horizon- A layer of soil that differs in
  color and texture from the layer above or below
  it.

12
How is soil made?

• Topsoil- The A horizon. Crumbly, dark brown soil
  that is a mixture of humus, clay, and other
  minerals.

13
How is soil made?

• Subsoil- The B horizon. Clay and other particles
  washed down from the A horizon.

14
How is soil made?

• C Horizon- forms as bedrock weathers and rock
  breaks up into soil particles.

15
Soil Types

• Scientists classify the different types of soil
  into major groups based on climate, plants, and
  soil consumption.

16
Where does humus come from?

• Living Organisms in Soil
• Litter- loose layer of leaves, twigs, and other
  dead plant matter

17
Where does humus come from?

• Decomposers- organisms that break down the
  remains of dead organisms into smaller pieces