Draw this pie chart describing the
composition of loam found in
Smyrna.
Question:
How much of this loam is
composed of decayed organic matter?
• MYP Unit Question: How does land change?
• Area of Interaction: Environment
What does this mean?
Surroundings, location
• Learner Profile: Caring and Principled What does this mean?
Honorable, Ethical,
Righteous, Moral
• Learning Target: I’m learning about soil
because our survival depends on it.
• Work Session: Soil Horizon Foldable
Standard
S6E5. Investigate the scientific view
of how the Earth’s surface is
formed.
d. Describe soil as consisting of
weathered rocks and
decomposed (decayed) organic
material.
Essential Question: Why do soil
horizons form the way they do?
Activator: What is soil anyway?
• Equipment Manager – quietly get a bin off the counter
• Recorder – make a chart similar to the one below
Material
Descriptions
1. Bedrock
2. Clay
3. Sand
4. Humus (Loam)
5.
• Task Manager – keep track of the time (10 minutes?)
• Directions: Feel each of the different types of soil.
As a group, use visual terms and describe each one.
• Equipment Manager
* Return a “clean” bin to the counter.
* Delegate someone to clean up the table.
How does soil form?
It takes a long time for soil
to form. Soil forms as rock
is broken down by
weathering and mixes
with other materials on
the surface. Soil is
constantly being formed
every time bedrock is
exposed. Over time, soil
develops layers. We call
these layers horizons.
There are 3 major
horizon layers:
Horizons A
B
C
Horizon A
• Horizon A is made up of topsoil. Topsoil is a
crumbly, dark brown soil that is a mixture of
humus, clay, and other minerals.
Horizon B
The B horizon is
called subsoil.
Subsoil consists of
clay and other
particles that have
washed down from
horizon A.
Horizon C
The first soil horizon
to form from the
weathering of bedrock
is the C horizon.
The C horizon contains
only partly weathered
rocks.
Below the C horizon is where
you will find bedrock.
Soil Horizons
Foldable—
1) Color your
“Horizon”
2) Glue into IAN
3) Write the
definition for
each horizon
use page
290 in text.
•
• Each state in the United
States has selected a state
soil, twenty of which have
been legislatively
established. These
“Official State Soils” share
the same level of
distinction as official state
flowers and birds.
• The state soil is a soil that
has special significance to
a particular state. Areas
with similar soils are
grouped and labeled as
soil series because their
similar origins, chemical,
and physical properties
cause the soils to perform
similarly for land use
purposes. A soil series
name generally is derived
from a town or landmark
in or near the area where
the soil was first
recognized.