1. What Is Soil?
Image: T. Loynachan
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2. Soil is a layer of unconsolidated material on the Earth’s surface in which plants grow.
Image: Louis Maher
Image: Professional Soil Classifiers Assoc. of Alabama
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3. Soil is a mixture of mineral grains from the Earth, decomposing organic matter, and voids filled with air or water.
Image: Professional Soil Classifiers Assoc. of Alabama
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4. Soil is the Earth material that links living things (biosphere), air (atmosphere), water (hydrosphere), and the solid Earth (geosphere).
Image: Bruce Molnia
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5. Different soil types develop in different climates.
Image: T. Loynachan
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6. Prairie soils have a dark surface layer (horizon), are rich in minerals, and form in grasslands widespread across Earth’s middle latitudes.
Images: NRCS
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7. Forest soils have a light gray upper horizon, a horizon rich in aluminum and/or iron, and form in warm to cool humid regions where coniferous forests grow.
Image: Soil Classifiers of Michigan
Image: Bruce Molnia
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8. Tropical soils are reddish and iron-oxide rich, depleted in nutrients, and form in humid and warm regions.
Images: National Cooperative Soil Survey, University of Nebraska
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9. Organic soils are dark colored, rich in decomposed organic matter, and form in poorly drained lowlands such as swamps and wetlands.
Images: Bruce Molnia, Soil Classifiers of Michigan
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10. Desert soils form in arid settings and are commonly rich in calcium carbonate.
Images: Martin Miller, NRCS
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11. Tundra soils form in Arctic environments, have a dark organic-rich upper layer, and a mineral rich layer over frozen ground.
Images: Travis Hudson, Alaska/Yukon Society of Professional Soil Scientists
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12. Different soil types develop in different climates.
Image: Image: T. Loynachan
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13. Sustaining Soils
Image: Digital Stock
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14. Soils can be degraded or destroyed.
Image: NRCS
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15. Soils need to be protected from erosion by wind and water.
Image: NRCS
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16. Soils need to be protected from depletion of organic matter and nutrients.
Image: NRCS
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17. Soils need to be protected from contamination.
Image: NRCS
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18. Soils need to be protected from urbanization.
Image: NRCS
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19. Degraded soils can be reclaimed.
Before
After
Images: Gold Institute, Echo Bay Mines; S. Warren
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20. Soils can be sustained through protecting and reclaiming.
Images: NRCS