Across
- 4. fertile soil
- 5. dark organic material in soil
- 8. change of set contour lines
- 10. the heavier contour lines
- 13. how we'll soil supports growth
- 14. planting different crops each year to increase fertility rate of the soil
- 15. the movement of weathered rock
- 17. In the Great Plains in 1930's the _______caused soil soil
- 20. physical weathering
- 23. tiny holes where water is able to seep through
- 25. preserving soil
- 28. plowing on the curves to prevent soil loss
- 30. thick mass of roots and soil
Down
- 1. lines on a topographic map
- 2. process that breaks down rock
- 3. the top layer of soil
- 6. mostly clay soil that is under the topsoil
- 7. map that uses line to show elevations
- 9. I dug in the ____ to find worms.
- 11. the way earth has changed over time
- 12. where crops are left to hold soil in place
- 16. anything in nature that humans use
- 18. when rock particles change the shape of a rock over time
- 19. Worms are a type of _____.
- 21. the process of rock removal with chemicals
- 22. thawing and freezing of water I between two rocks
- 24. the solid layer of rock under earths surface
- 26. the layers of different soil
- 27. layer of dead organic material
- 29. a change when substances rusts