Soil Flashcards
What soil forms from
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Mechanical and chemical processes
What soil consists of
Regolith,
Humus,
Water, and
Living Organisms
Minerals and weathered rock fragments
Regolith
Weathered rock particles and decaying organic matter
Humus
Soil varies in composition, texture, structure,
and color at different depths.
Soil profile
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The 3 soil horizons
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O/A, B, C
O/ A
Topsoil
B
Subsoil
C
Bedrock
Topsoil (O/A)
Organic material, loose leaves, lots of insects/ microorganisms
Subsoil (B)
Fine clay and lower limit of plant roots
Bedrock (C)
Parent material. Contains little organic matter.
Factors of soil formation
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Climate. Typography. Parent material. Biological organisms, and Time.
Most significant factor of soil formation. Temp, wind, and amount of rain determine composition of the soil.
Climate
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Slope of ground and orientation towards the sun
Topography
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Material that has been transported by erosion will have different characteristics than the original soil
Parent material
Microorganisms, fungi, bacteria contribute different organic materials to the soil
Biological organisms
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Newer soils are found along rivers where erosion has taken place and minerals are present. Older soils have had most minerals changed/washed away
Time
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Types of soil
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Pedalfer. Pedocal. Laterites.
Soils that are rich in Aluminum and Iron
Pedalfer
These soils form in forested, humid climates like the southern U.S. They have a lot of clay in them and are red- brown in color.
Pedalfer
These soils are rich in calcium and form in dry, arid climates (like southwestern U.S. Ground is covered in grasses and brush vegetation. Light- grey- brown color
Pedocal
Soils that have been depleted of almost all elements except for iron and aluminum oxides. They form in hot, tropical areas, where lots of rain filters minerals, giving it a color of orange or red.
Laterites
High rainfall has caused leaching on most of the elements and nutrients from the soil.
Laterites
This is the soil of a tropical rainforest.
Laterites
When dried, it become very hard and practically waterproof. Ancient structures were built from these soils.
Laterites
