G chapter 2

1. thick mass of grass roots and soil
4. A material that is full of tiny connected air spaces that water can seep through
5. Grinding away of rock by other rock particles carried in ice, water,or wind
7. Line that connects points with the same elevation on a topographic map
8. Solid layer of rock beneath the soil
11. rocks broken down chemically
12. measure of how well soil supports plant growth
15. Rocks that break down on Earths Suface physically and chemically
16. Horizon Layer of soil that differs in color and texture
19. The crumbly, topmost layer of soil, mixture of humus, clay, and other minerals
20. When water, ice, wind, or gravity moves weathered rock or soil
21. plowing fields along curves of slopes to prevent soil loss
22. Method which dead stalks from the previous years crops are left in the ground to hold soil in place
23. The distance in elevation from Contour line to Contour line
26. A map that shows Suface area
28. Anything in the environment that humans use

2. Chemical change when when a substance combines with oxygen
3. A soil organism that breaks down the remains of organisms and digests them
6. rocks broken down physically
9. Layer of soil beneath the topsoil, contains clay and other minerals
10. Darker contour line on a topographic map that rounds elevation units
13. The process when water seeps into cracks, freezes and expands
14. Principle that states that earth surface changed the same way forever
17. area of the Great Plains where wind erosion caused soil loss in the 1930s
18. management of soil to prevent destruction
22. Planting of different crops in fields each year to maintain soils fertility
24. type of soil that is made up of about equal parts of clay, sand, and silt
25. Loose layer and dead plant leaves and stems on the Suface of the soil
27. Dark colored organic material in soil