Soil

1. layers

1.1. Organic

1.2. Top Soil

1.3. Sub Soil

1.4. Parent Material

1.5. BedRock

2. Types

2.1. Sand

2.2. Clay

2.3. Silt

3. is made of

3.1. weathered rocks

3.1.1. sand

3.1.2. silt

3.2. organic matter

3.3. definition

3.3.1. Nutriance

3.3.2. made of

4. Description

4.1. Tropical

4.2. Desert

4.3. Grassland