| A | B |
|---|
| soil | The loose material in which plants can grow in the upper layer of Earth. |
| Humus | The part of soil made up of decayed parts of once-living things. |
| Topsoil | The top layer of soil. |
| Clay | Soil that has small grains and small spaces between the grains. |
| Loam | Rich soil with lots of humus. |
| resource | A material found in nature that living things use. |
| conservation | Saving resources by using them carefully. |
| strip cropping | Planting strips of grass between crops. |
| contour plowing | Planting crops around a hillside instead of up and down. |
