Chapter 2

3. area of the Great Plains where wind erosion cause lack of soil in the 1930's
5. management of soil to prevent destruction
8. the process that uses water, wind, ice, or gravity to move weathered rock and soil
10. type of weathering that is physically broken into pieces
15. loose layer of dead plants and stems on the surface of soil
16. solid layer of rock beneath the soil
18. lines on a topographic map used to show the elevation
21. the difference in elevation from one contour line to another
23. soil organism that breaks down other organisms
27. a darker contour line that is labeled with the elevation
28. water the seeps into cracks, freezes, and then expands
29. layer in soil that is a different color from the ones above and below it

1. dark colored organic material in the soil
2. material on earths surface in which pants grow
4. chemical change that when mixed with oxygen creates rust
6. thick bunch of grass roots and soil
7. anything found in nature that humans use
9. the geological principle that uses the same process as in the past as we do today
11. conservation method that uses dead stalks to keep soil in place for next years crops
12. weathering process that breaks down rocks chemically
13. the process that uses either chemical or physical changes to break down earths surface
14. map using contour lines to show an elevation of an area
17. plowing fields to prevent soil loss around curves
19. humus, clay, and other minerals that forms on the uppermost layer of soil
20. planting crops in a different lace each year to keep soil fertile
22. when a material has oxygen holes that water seeps through
24. the grinding away of rocks using water, ice, or wind
25. layer of soil underneath the topsoil that is mostly made of clay
26. measurement of how well plants grow
30. rich soil that is made from clay, sand, and silt