| A | B |
|---|
| weathering | the process that breaks down rock into small pieces |
| erosion | the process where small particles of weathered rock are moved by wind, water, ice and gravity |
| soil | the loose, weathered material on Earth's surface in which plants can grow |
| bedrock | the solid layer of rock found beneath the layers of soil |
| humus | dark-colored material in the soil that is the remains of plants and animals |
| loam | rich, fertile soil made of equal parts of clay, sand and silt |
| soil horizon | a layer of soil that is different from the layers above or below it |
| topsoil | the top layer of soil that contains humus and other materials |
| subsoil | the layer of soil beneath the topsoil that is made of mostly clay |
| soil conservation | managing soil to prevent its destruction or loss |
