| A | B |
|---|
| soil | loose material in which plants can grow in the upper layer of Earth |
| humus | the part of soil made up of cedayed parts of once-living things |
| topsoil | the top layer, made up of the smallest grains, richest layer |
| bedrock | the layer of solid rock under the soil |
| clay | soil that has small grains and holds water easily |
| loam | rich soil with a lot of humus, water and air |
| resource | a material found in nature that living things use |
| conservation | saving resources by using them carefully |
| strip cropping | planting strips of thick grass or clover between rows of crops |
| contour plowing | planting rows of crops around the sides of hills instead of up and down |
