Science

3. loose, weathered material on Earth's surface where plants can grow
6. grinding away of rock by other rock particles carried away by wind, ice, or water
8. a type of map that shows the surface features of an area
10. a characteristic of a material that is filled with very tiny air spaces that water can seep through
11. process that splits up rocks when water seeps into cracks, freezes, and expands
12. planting of different crops in a field each year to maintain the soils fertility
13. a loose layer of dead plant leaves and stems on the surface of soil
15. thick mass of grass roots and soil
16. dark-colored organic material that is in soil
19. soil conservation method in which dead stalks from previous years crops are left on the ground to hold the soil in place
22. the measure of how well soil can support plant growth
23. a solid layer of rock beneath the soil
24. a darker contour line that is labeled with the elevation
26. anything in the environment that humans use
27. a layer of soil beneath the topsoil that contains mostly clay, other minerals
28. management of soil to prevent its destruction
29. rich, fertile soil that is made up with (about) equal parts of clay, sand, and silt

1. process by which water, ice, wind, or gravity moves weathered rock and soil
2. a soil organism that breaks down the remains of organisms and digests the
4. a chemical change when a substance combines with water (when iron oxidizes, it forms rust)
5. plowing fields along the curves of a slope to prevent the loss of soil
7. type of weathering is where rock is broken up physically into smaller pieces
9. process that breaks down rocks by chemical changes
14. a line on a topo map shows points of equal elevation
17. a geological principle that the same geological processes that operate today have operated in the past to hange the Earth's surface
18. a layer of soil that differs in color and texture from the layers above and below it
19. the difference in elevation from contour line to contour line
20. a mixture of clay, humus, and other minerals that forms the crumbly, topmost layer of soil
21. a chemical or physical process that breaks down rocks from the Earth's surface
25. area of the Great Plains where wind erosion caused soil lost in the 1930's