Download Formation of Soil lesson 3

Formation of Soil
UNIT 5
STANDARDS:
STATE OBJECTIVES: NCES 2.1.1, 2.1.3, 2.1.4
LESSON 3
Lesson Objectives
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In this lesson, you will learn about:
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How soil forms
The relationship between organic and
inorganic components in the soil
Be able to identify some soil characteristics
Recognize soil horizons in a soil profile
Development of Soil
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What is soil?
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Soil is the loose covering of
broken down rock particles
and decaying organic matter
overlying bedrock.
Soil is the result of chemical
and mechanical weathering.
Bacteria and fungi break down
organic material adding
nutrients to the soil.
Basic Process of Soil Creation
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Role of Bacteria
Role of Nutrients
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Soil Texture
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Water retention
Simple comparison
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Bacteria break down
organic material
Nutrients in the soil aid
in plant growth
Texture refers to grain
size (sandy…clay)
Water retention increases
with organic material
Compare potting soil to
sand
Soil Composition
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What is parent soil?
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What is transported
soil?
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Parent soil comes from
the weathering of the
underlying bedrock into
smaller pieces. This
determines the basic
mineral composition.
Transported soil is soil
that has been moved from
its origin to the section of
soil. Erosion is the main
agent of soil transport.
Soil Profile
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What is a soil profile?
What are the different
layers?
What are the 3 soil
horizons?
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A soil profile is a vertical
sequence of soil layers.
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Each distinct layer of the soil
is called a soil horizon.
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Horizon A: Rich organic
material and humus.
Horizon B: generally
characterized by rich clays, no
water loss.
Horizon C: Sits on bedrock
and is weathered bedrock.
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Parts of the Soil Profile
Horizon O
Horizon A
Horizon B
Horizon C
Horizon R
Soil Types
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What determines the
different soil types?
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*Soils are classified
based on the climate.
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Soils form from
parent bedrock.
Plants and animals
living in and on the
soil.
Length of time soil
has been forming.
Climatic conditions
Polar Soils
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Characteristics
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Form at high altitudes
Greenland, Canada, Antarctic
Good drainage
NO distinct horizons
Very shallow, few inches
What is permafrost
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Permanently frozen ground
Temperate Soils
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Characteristics
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Grasslands
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Forests
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Praries
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Great Plains to forests
Annual rain 50-60 cm
Abundance of Humus
Rich soils
Less deep Less fertile
Rich clays
Less than 50-60 cm rain
Only support brush
Examples of Temperate Soils
Desert Soils
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Characteristics
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Receive low amounts
of rain < 25cm per yr
High levels of salts
Little to no organic
material
Light colored
Course grain, sand
Tropical Soils
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Characteristics
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High Temperatures
High rainfall
Often infertile due to
high levels of plant
acids and salts
Little humus
Little nutrients
*Remember rain
washes it away
Soil Fertility
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What is fertility
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How well the soil can
support the growth of
plants.
Mineral content and
nutrients determine
Commercial fertilizer
Compost
Mulch and Peat
Lesson Review
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Synthesis: Explain the stages involved in
soil formation
Application: Describe three characteristics
of soil
Evaluation: Explain the difference between
temperate and tropical soil
Relativity: Investigate the cost to fertilize a
yard (40,000 sq. feet) using 10-10-10