Across
- 2. a chemical change, a stubstance combines with oxygen, then forms rust
- 4. soil organasims that breaks down organisms & digest them
- 7. bowl- the great plains, wind erosion of soil loss in the 1930's
- 8. planting new in a feild each year to maintain soils fertility
- 10. a map that shows surface features of an area
- 15. the process if either ice, water, wind or gravity moves rock or soil
- 17. a type of weather that rock is broken down into smaller pieces
- 19. a measure of how well soil supports plant growth
- 22. a topo map, a heavier contour line is labled with round units
- 23. when water seeps in a crack in a rock & freezes and expands
- 25. the layer beneath the topsoil that makes up clay and other minerals
- 26. the difference in elevation from one contour line to the next
- 28. dark colored organic material in soil
- 29. the loose layer of dead plant leave & stems on the surface of the soil
Down
- 1. the chemical & pysical processes that break down rock on earths surface
- 3. the solid layer of rock beneath the surface
- 5. they layer of soil that differs than the bottom or top soils
- 6. anything in a envirorment humans use
- 8. when rock breaks down by chemical changes
- 9. the managment of soil to prevent its destruction
- 11. a line on a topo map that connects points of equal elevation
- 12. a meterial full of tiny, connected air spaces water can seep through
- 13. loose, weathered material on earths surfuce in which plants can grow
- 14. soil conservation, dead stalks hold the soil in place
- 16. the geological prinsiple changes over time
- 18. rich fertile soil that is made up of most equal parts of clay, sand, and silt
- 20. the grinding away of rock by other rock particles carried in water or ice
- 21. a thick mass of grass roots and soil
- 24. plowing feilds along the curves of a slope so loss soil
- 27. a mixture of humas, clay, that forms crumbly, topmost layer of soil