SOIL PROFILES

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SOIL PROFILES
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Objectives

• Determine what layers a soil profile contains
• Identify various types of soil profiles
• Explain the role that water plays in the
  formation and movement of soil
• Create a soil profile
• Observe how liquid travels through the soil
  profile

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What is a soil profile?

• O horizon organic material
• A horizon topsoil
• E horizon
• B horizon
• C horizon parent material
• R horizon - bedrock

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Soil Layers

• O Horizon where plant roots grow
• top layer of soil
• where animals live
• fresh to partially decomposed organic matters
• color varies from brown to black
• Organic soil is produced by the build-up of plant
  material and are the most productive/fertile
  soils.

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Soil Layers

• A Horizon Topsoil
• made of highly decomposed organic matter
• color range from brown to gray
• E Horizon area of topsoil that has little
  organic material leached out
• made up of mostly sand and silt
• lost most of its minerals and clay due to
  eluviation

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Soil Layers

• B Horizon where leached materials gather
• more clay and bigger bedrock
• reddish brown or tan in color
• C Horizon parent material
• mostly weathered bedrock
• cracked and broken surface of the bedrock

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Soil Layers

• R Horizon bedrock
• last layer in the profile
• consists of unweathered rocks
• The process of weathering rocks is slow and
  occurs over thousands of years.

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Water Movement

• Water is the major force responsible for moving
  soil from one place to another.
• Infiltration the process of water entering the
  soil
• If soil is dry the water will infiltrate faster
  but once the soil is wet infiltration will slow
• Water is leading cause of erosion
• Erosion is the process of soil particles being
  moved by water or wind.

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Water Movement

• Water movement is affected by three factors
• Gravity forces water to move downward
• Capillary action Movement of water along
  microscopic channels by two forces
• Adhesion
• Absorption
• Soil porosity - volume of water that can be held
  in a soil

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Create a Soil Profile

• Horizon C
• Horizon B
• Horizon A
• Horizon O

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Objectives

• Determine what layers a soil profile contains
• Identify various types of soil profiles
• Explain the role that water plays in the
  formation and movement of soil
• Create a soil profile
• Observe how liquid travels through the soil
  profile

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Review Identify layers of a soil profile and
one distinguishing characteristic