Chapter 2

3. layer in soil that is a different color from the ones above and below it
7. soil organism that breaks down other organisms
10. conservation method that uses dead stalks to keep soil in place for next years crops
13. plowing fields to prevent soil loss around curves
15. a darker contour line that is labeled with the elevation
16. weathering process that breaks down rocks chemically
18. planting crops in a different lace each year to keep soil fertile
19. humus, clay, and other minerals that forms on the uppermost layer of soil
21. map using contour lines to show an elevation of an area
24. the geological principle that uses the same process as in the past as we do today
27. area of the Great Plains where wind erosion cause lack of soil in the 1930's
28. the process that uses either chemical or physical changes to break down earths surface
29. measurement of how well plants grow
30. material on earths surface in which pants grow

1. the process that uses water, wind, ice, or gravity to move weathered rock and soil
2. management of soil to prevent destruction
4. chemical change that when mixed with oxygen creates rust
5. loose layer of dead plants and stems on the surface of soil
6. solid layer of rock beneath the soil
8. type of weathering that is physically broken into pieces
9. the difference in elevation from one contour line to another
11. thick bunch of grass roots and soil
12. rich soil that is made from clay, sand, and silt
14. anything found in nature that humans use
17. the grinding away of rocks using water, ice, or wind
20. lines on a topographic map used to show the elevation
22. when a material has oxygen holes that water seeps through
23. dark colored organic material in the soil
25. water the seeps into cracks, freezes, and then expands
26. layer of soil underneath the topsoil that is mostly made of clay