Soil and erosion: practice questions
Use the question plan again. Remember soil facts. The nonliving, or abiotic, parts of soil are rock pieces, air and water. Humus and decomposers are the living or once-living, organic parts. Weathering breaks rock into small pieces and erosion carries them away. From largest to smallest, the particles are sand, silt and clay. Soils with large spaces between particles let water drain fast and hold little. Plants of dry, loose soil include grasses and desert shrubs, not water plants. Desertification can result from cutting down too many trees, overgrazing and drought. Planting trees and grasses slows erosion by wind and water, and trenches across a slope slow water.
| Soil fact | Answer |
|---|---|
| abiotic parts | rock pieces, air, water |
| organic part | humus and living things |
| largest to smallest | sand, silt, clay |
| slows both wind and water erosion | planting trees and grass |
| Soil | Time to drain |
|---|---|
| A | 20 seconds |
| B | 4 minutes |
Soil quiz. With a grown-up, write three questions about soil on cards. Swap them with a friend. Mark each other’s answers and ask for a reason each time.