1. Soil Origin and Development
Chapter 2
Soil Origin and Development
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Soil Science & Management, 4E

2. Soil Science & Management, 4E
Objectives
Define a soil body
List examples of five soil-forming factors
Describe how soils develop
Describe the horizons of a soil profile
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3. Soil Science & Management, 4E
Terms to Know
Glacial till
Hydrolysis
Igneous rock
Illuviation
Lacustrine
Leaching
Levee
Loess
Marine sediment
Master horizon
Metamorphic rock
Alluvial fan
Alluvial soil
Chemical weathering
Colluvium
Delta
Eluviation
Eolian deposit
Floodplains
Frost wedging
Glacial drift
Glacial outwash
(continued)
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4. Soil Science & Management, 4E
Terms to Know
Mineral soil
Organic soil
Oxidation-reduction
Parent material
Pedology
Pedon
Physical weathering
Plow layer
Polypedon
Residual soil
River terrace
Root wedging
Sedimentary rock
Soil genesis
Soil horizon
Soil profile
Solum
Solution
Subsoil
Talus
Topsoil
Transported soil
Weathering
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5. Soil Science & Management, 4E
The Soil Body
Figure 2-1
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Soil Science & Management, 4E

6. Soil Science & Management, 4E
Rocks and Minerals
Igneous rock
Sedimentary rock
Metamorphic rock
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7. Soil Science & Management, 4E
Rocks and Minerals
Figure 2-4
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8. Soil Science & Management, 4E
Igneous Rock
Figure 2-5
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9. Soil Science & Management, 4E
Metamorphic Rock
Figure 2-6
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Soil Science & Management, 4E

10. Soil Science & Management, 4E
Parent Material
Figure 2-8
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11. Soil Science & Management, 4E
Parent Material
Glacial ice
Wind
Water
Gravity
Volcanic deposits
Organic deposits
Figure 2-9
Figure 2-11
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12. Soil Science & Management, 4E
Climate
Figure 2-13
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13. Soil Science & Management, 4E
Organisms
Figure 2-14
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14. Soil Science & Management, 4E
Topography
Influences soil development mainly by affecting water movement
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15. Soil Science & Management, 4E
Time
Soils change over time due to aging process
Humans
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16. Soil Science & Management, 4E
The Soil Profile
Master horizons
Subdivisions of master horizons
Figure 2-19
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17. Soil Science & Management, 4E
Summary
Soils form from minerals broken up by action of weathering, plant roots, and the addition of decaying plant parts
Five factors govern soil development:
- Parent material
- Climate
- Life
- Topography
- Time
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Soil Science & Management, 4E