Across
- 1. plowing fields along curves of a slope
- 3. a loose layer of dead plant leaves and stems on the top of the soil
- 5. rich, fertile, soil that is made of clay, sand, and silt
- 6. a mixture of soil that contains humus, clay, and other matereials
- 9. the principal which the process of weathering hasn't changed
- 11. a thick layer of f grass and roots
- 12. the difference in elevation on a map
- 13. a chemical change that forms rust
- 14. the different layers of soil
- 15. the process which breaks down rocks whith chemical chances
- 17. the process which breaks down a rock at Earth's surface
- 18. a map that tells the features of a place
- 22. when roots are left in the ground to hold the soil
- 27. a soil organism that breaks down dead organisms and digest them
- 28. a solid layer of rock beneath the soil
- 29. the area of the Great Plains where wind caused soil loss
- 30. how well soil supports plants
Down
- 2. human resources from the environment
- 4. planting different crops in a field each year to hold the fertility steady
- 7. the process that moves weathered rock and soil
- 8. the process when water gets into ice, freezes, and expands
- 10. the process which rock is broken into smaller pieces
- 16. dark, organic, material in soil
- 19. a line on a topographic map that connects elevation points
- 20. the layer of soil beneath the topsoil
- 21. the management of soil to prevent destruction
- 23. material on Earth's crust that plants grow in
- 24. grinding of rock by water, wind, and ice
- 25. a heavier contour line that is labeled with it elevation in a round unit
- 26. a characteristic of something that has small holes for water to seep into