Soil

1. is made of

1.1. organic matter

1.1.1. nutrients

1.2. weathered rocks

1.2.1. sand

1.2.2. silt

1.2.3. clay

2. types of soil

2.1. Tropical grassland

2.2. Forest

2.3. Grassland

2.4. desert

3. what soil needs

3.1. water

3.2. air

3.3. nutrients

4. Described using

4.1. texture

4.1.1. grainy

4.1.2. silky

4.1.3. sticky

4.2. consistence

4.2.1. loose

4.2.2. friable

4.2.2.1. firm

4.3. color

4.3.1. chocolate brown

4.3.1.1. yellow

5. layers

5.1. top soil

5.1.1. has rock, sand, silt, clay, organic matter, air and water. About 20 cm deep and very rich in nutrients.

5.2. subsoil

5.2.1. not much organic matter, contains some chemicals found in topsoil

5.3. parent material

5.3.1. broken rock and very little organic matter

5.4. bedrock

5.4.1. hard rock