1. Earth & Soil

2. Earth: Formed 4.6 Billion Years ago. Three section:
1. Biosphere: All life on land and water
2. Hydrosphere: All forms of water.
3. Internal Structure:
Crust
Mantle
Core

3. Lithosphere Crust and Upper Mantle
Creates movable plates on the surface of Earth

4. Plate Tectonics
Seafloor spreading along the plate boundary

5. What happens where the plates come together
________

6. Rock Cycle Fossils
Ex. Basalt
Granite

7. SOIL / Not Dirt!!! Thin layer on top of most of the earth land surface

8. Soil is composed of three main ingredients
1. Minerals & organic materials
2. Air
3. Water

9. Soil Profile

10. Soil Composition Clay: Very fine particles. Low permeability.
Soil can become water logged
Silt: Fine Sedimentary material.
Loam: Mixture of Clay, silt, sand and *Humus.
Sand: Medium size Sedimentary material. Water flows through easily.
Gravel: Course sedimentary material. Small rocks
*Humus: Dark organic matter from decomposition.

11. USDA Soil Texture Chart

13. Soil Erosion Sheet: Soil moves off as a horizontal layer.
Rill: Fast moving water cuts small channels
Gully: Extreme case of Rill erosion

14. Desertification: The creation of “Desert-like” conditions due to over grazing, over cultivation, and excessive irrigation

15. Salinization: Water that’s not absorbed and evaporates leaving behind dissolved salts in the topsoil .

16. Dust Bowl 1930’s

17. Plowing the prairie resulted in loss of natural grasses that rooted the soil. Drought and winds blew most of the top soil away!!

18. Relevant Laws Soil Conservation / Erosion Act 1935.
Established Soil Conservation Service. Protect the soil. Paid farmers not to grow crops in some areas.
Soil and Water Conservation Act
Requires USDA to periodically prepare a national plan for soil and water conservation