Soil

1. the dust bowl

1.1. Oklahoma

1.1.1. texas

1.2. texas

1.3. new mexico

1.4. 1930

2. organic matter

2.1. made up of dead animals

3. Soil needs

3.1. N-Nitrogen

3.2. P-Phosphorus

3.3. K-Potassium

3.4. Water

4. weathered rocks

5. soil layers

5.1. topsoil

5.2. subsoil

5.3. parent material

5.3.1. bedrock

5.4. bedrock

6. soil types

6.1. sandy soil

6.2. rich soil

6.3. colored soil

7. sand, clay, silt