science tic tac toe

3. management of soil to prevent its destruction
5. soil organism that breaks down the remains of organisms and digests them
7. loose weathered material on earth’s surface where plants grow
8. area of the great plains where wind erosion caused soil loss during the 1930s
10. process that splits rock when water seeps into cracks then freezes and expands
13. geologic principle that the same geologic processes that operate today operated in the past to change Earth’s surface
16. planting of different crops in a field each year to maintain the soil’s fertility
18. anything in the environment that humans use
20. measure of how well soil supports plant growth
21. layer of soil beneath the topsoil that contains mostly clay and other minerals

1. grinding away of rock by other rock particles carried in water, ice or wind
2. loose layer of dead plant leaves and stems on the surface of the soil
4. chemical and physical processes that break down rock at Earth’s surface
6. layer of soil that differs in color & texture from the layers above or below it
9. thick mass of grass roots and soil
11. process by which water, ice, wind or gravity moves weathered rock or soil
12. characteristic of material that is full of tiny, connected air spaces that water can seep through
14. mixture of humus, clay and other minerals that forms crumbly, topmost layer of soil
15. solid layer of rock beneath the soil
16. plowing fields along the curves of a slope to prevent soil loss
17. chemical change in which a substance combines with oxygen, as when iron oxidizes forming rust
19. dark colored organic material in soil