Chapter 2

7. when a material has oxygen holes that water seeps through
8. weathering process that breaks down rocks chemically
10. conservation method that uses dead stalks to keep soil in place for next years crops
14. the grinding away of rocks using water, ice, or wind
16. water the seeps into cracks, freezes, and then expands
18. thick bunch of grass roots and soil
21. humus, clay, and other minerals that forms on the uppermost layer of soil
22. the geological principle that uses the same process as in the past as we do today
24. loose layer of dead plants and stems on the surface of soil
25. a darker contour line that is labeled with the elevation
28. dark colored organic material in the soil
29. the process that uses either chemical or physical changes to break down earths surface
30. plowing fields to prevent soil loss around curves

1. anything found in nature that humans use
2. soil organism that breaks down other organisms
3. layer of soil underneath the topsoil that is mostly made of clay
4. material on earths surface in which pants grow
5. layer in soil that is a different color from the ones above and below it
6. type of weathering that is physically broken into pieces
9. planting crops in a different lace each year to keep soil fertile
11. map using contour lines to show an elevation of an area
12. chemical change that when mixed with oxygen creates rust
13. the difference in elevation from one contour line to another
15. solid layer of rock beneath the soil
17. lines on a topographic map used to show the elevation
19. rich soil that is made from clay, sand, and silt
20. measurement of how well plants grow
23. management of soil to prevent destruction
26. area of the Great Plains where wind erosion cause lack of soil in the 1930's
27. the process that uses water, wind, ice, or gravity to move weathered rock and soil