1. Soil Conservation
Section 3
Ms. Musich

2. Activating Prior Knowledge
Think of an area of land that has a wide are of dirt like a construction site or a vacant lot…

3. What do you think happens to an area like this when it rains?
What is the water like that runs off the area?
Is there anything that could be done to prevent this erosion of soil?

4. If you were in the 1800s…
You would have seen lots of prairies on your settler’s journey. (Think Oregon Trail)
Prairie soil is very fertile and is rich with humus.
Sod –the thick mass of tough roots at the surface of the soil keeps it in place and holds onto moisture.

5. The Value of Soil
Soil is one of Earth’s most valuable resources because everything that lives on land depends directly or indirectly on soil.
Plants depend on soil to live and grow.
Animals depend on plants (or animals that eat plants) for food.
Soil formation can take hundreds of years for just a few centimeters of soil to form.

6. The Value of Soil (cont’d)
Fertile soil is very valuable because less than one-eighth of the land on Earth has soil that is well suited for farming.
What does it mean for soil to be fertile?
What substance must be in soil for it to be fertile?

7. Soil Damage and Loss Soil is so important, but can be damaged or lost.
Soil can lose its fertility.
This happened in the South in the late 1800s when cotton was the only crop grown on farms.
In the early 1900s, George Washington Carver developed new crops and farming methods to make the soil fertile again.

8. Fertile vs. Not

9. George Washington Carver 1864-1943

10. The Dust Bowl
As settlers began settling among the Great Plains, they began plowing the earth.
Why do you think these settlers plowed the earth?

11. The Dust Bowl
Plowing removed the grass from the Great Plains and exposed the soil. In times of drought, the topsoil quickly dried out, turned to dust, and blew away.

13. Soil Conservation
After the Dust Bowl, people began to realize how important soil is and developed new farming techniques.
Soil conservation is the management of soil to prevent its destruction.
Two ways that soil can be conserved include contour plowing and conservation plowing.

14. Contour Plowing
Contour plowing is the practice of plowing fields along the curves of a slope.
This helps slow the runoff of excess rainfall and prevents it from washing the soil away.

15. Conservation Plowing
Conservation plowing disturbs the soil and its plant cover as little as possible.
Dead weeds and stalks of the previous year’s crop are left in the ground to help return soil nutrients, retain moisture, and hold soil in place.