Download Components and Properties of Soil

Soil
Objective: I will be able to explain
what soil is and why it is important by
creating an illustration
What is soil?
Material which nourishes and supports
growing plants includes rocks, water,
organic material and air.
How is soil formed?
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Rocks rubbing together for many, many years
Organic matter
What is our State……
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Soil…..
Jory
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Rock…..
Thunder
Egg
What is a Thunder Egg
According to ancient Native American legend, when the
Thunder Spirits living in the highest recesses of
snowcapped Mount Hood and Mount Jefferson became
angry with one another, amid violent thunder and
lightning storms they would hurl masses of these
spherical rocks at each other. The hostile gods obtained
these weapons by stealing eggs from the Thunderbirds'
nests, thus the source of the name "Thundereggs."
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A Thunder egg is not actually a rock. It is a
structure, sometimes a nodule, sometimes a
geode,
Why is soil important?
 It
supplies water, nutrients, and a
medium for plants
 Acts as a filter
 https://login.icevonline.com/mycours
es/DUNDA002/lesson/143
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What are the functions of soil?
Plant medium
Recycling system for nutrients
Habitat for organisms
System for water supply
Water purification
Support foundation
Heat storage
Decomposes organic material
Buffer of toxic compounds to
the environment
Source of raw materials
Gene pool
Source of history
Video
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iCEV Video soil formation and evaluationimportant.
https://login.icevonline.com/mycourses/DUN
DA002/lesson/143
What are Soil Horizons?
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As soils develop they form layers called
Horizons.
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O Horizon
O
Layer of accumulated
organic matter such as
leaves, grass, twigs
Material can be in various
states of decomposition
Generally dark in color
A
E
B
C
R
A Horizon
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Topsoil
Generally it is the most
productive horizon
High biological activity
Generally dark in color
O
A
E
B
C
R
E Horizon
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Leached soils
Soluble minerals and
organic material move out
of this horizon
Generally a lighter
“washed” appearance in
color
O
A
E
B
C
R
B Horizon
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Less amount of parent
material break down and
organic matter.
Often more course
fragments (rock visible)
Varies in color from reds
and yellows to browns and
grays
O
A
E
B
C
R
C Horizon
The unconsolidated
material that has been
affected little by the soil
forming processes
 Course fragments
present
O
A
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E
B
C
R
R Horizon
Hard bedrock
 100% course fragments,
also known as rock
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O
A
E
B
C
R
Video
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iCEV video Soil Fertility and Productivity
Assignment
You will complete a soil profile on the left
side of your notebook
 You must have each horizon in your
profile
 Each horizon must be colored accordingly
 Include characteristics of each horizon
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Soil Differs in:
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Texture
Color
Structure
Consistence
Fertility and Productivity
Soil Texture
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The way soil feels
Based on the relative proportions of each size of
soil particle
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Sandy loam, Silty loam, Sandy Clay loam
Why is soil texture important?
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Influences many soil properties
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drainage, water holding capacity, aeration,
susceptibility to erosion, organic matter content,
cation exchange capacity, pH buffering capacity, and
soil tilth
Soil Texture - Relative Sizes of
Soil Particles
Sand (0.05-2.00 mm)
Silt (0.002-0.05 mm)
Clay (<0.002 mm)
Sand
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Larger particles in the soil
Can be seen with the naked eye
Not fertile
Quick to dry out and are doughy
Drain quickly
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Silt
Between sand and clay particles in size, medium
size
Provide few nutrients to plants
Erode every easily
Moderate drainage
Clay
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Smallest of the soil particles
Hold soil nutrients
Hold more moisture than either sand or silt
Dry out slowly
Become cloddy unless properly managed
What is loam?
The Best of All Worlds
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A soil type that contains all three particle sizes.
The most productive soil for farming crops
Has good water holding capacity (from clay)
 Has good drainage (from sand)
 Can be nutritious (from silt)
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Soil Texture Lab
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That person go get 1 of each of the bowls from
up from (sand, Silt, and Clay)
Put the bowls in the center of the table
NO ONE TOUCH THEM OR THE LAB IS
OVER!!!!
Once everyone is done another person bring the
bowls back up from.
Wait until everyone is done
Copy down the following
Define the following words:
Clay
Sand
Silt
Using the cups filled with Sand, Slit, and Clay,
describe what you see, feel, hear, ect.
Sand
Silt
Clay
12 Soil Texture Classes
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Sand (S)
Loamy Sand (LS)
Sandy Loam (SL)
Loam (L)
Silt Loam (SIL)
Silt (SI)
Sandy Clay Loam (SCL)
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Silty Clay Loam (SICL)
Clay Loam (CL)
Sandy Clay (SC)
Silty Clay (SIC)
Clay (C)
Compositions of each of the 12 texture classes is defined by
the USDA Soil Triangle
Soil
Texture
(paste
in)
Soil Triangle Problems
Using the Soil Triangle find the
following soils:
Has to equal 100% at the end!!
Sand: 40%
Silt: 30%
Clay: 30%
Clay
Loam
Sand: 70%
Silt: 20%
Clay: 10%
Sandy
Loam
Sand: 20%
Silt: 70%
Clay: 10%
Silty
Loam
Assignment
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Soil Triangle problems