1. Soil, an Essential Natural Resource
S6E5h. Describe soil as consisting of weathered rocks and decomposed organic material

2. What is soil?
Key terms:
Soil—the loose, weathered material on Earth’s surface in which plants can grow.

3. What is soil?
Key terms:
Soil—the loose, weathered material on Earth’s surface in which plants can grow.
“soil” v. “dirt”—dirt gets on our clothes and in our house, and we don’t want it there; soil is what plants need to grow

4. What is soil?
Key terms:
Soil—the loose, weathered material on Earth’s surface in which plants can grow.
Bedrock—the solid layer of rock beneath the soil.

5. What is soil?
Key terms:
Soil—the loose, weathered material on Earth’s surface in which plants can grow.
Bedrock—the solid layer of rock beneath the soil.
Soil horizon—a layer of soil that differs in color and texture from the layers above or below it.

6. What is soil made of?
Soil is a mixture of rock particles, minerals, decayed organic material, water, and air. Humus—a dark-colored substance that forms as plant and animal remains decay. It has nutrients plants need, making the soil fertile. Fertility measures how well soil supports plant growth.

7. What is soil made of?
Soil is a mixture of rock particles, minerals, decayed organic material, water, and air. Loam—soil consisting of about equal parts of clay, sand, and silt.

8. How is soil formed? Three main soil horizons:
Soil horizon A—topsoil—dark soil mixture of humus, clay, and other minerals
Soil horizon B—subsoil—the middle layer, consisting of clay and other particles washed down from the A horizon, but little humus
Soil horizon C—weathered bedrock, bottom layer, first layer to form

9. How is soil formed?

10. How is soil formed?
Order of formation: C  A  B

11. How do scientists classify soil types?
Soil is classified into groups based on climate, plants and soil composition.
List and describe five different soil types
What type of soil do we have in Georgia?

12. What is the role of plants and animals in soil formation?
Key terms
Litter—loose layer of dead plant leaves and stems on the surface of the soil
Plants provide most of the organic material found in soil. Plant remains contain lots of stored nutrients, which can help to make soil fertile.

13. What is the role of plants and animals in soil formation?
Key terms
Litter—loose layer of dead plant leaves and stems on the surface of the soil
Decomposers—organisms that break the remains of dead organisms into smaller pieces and digest them with chemicals

14. What is the role of plants and animals in soil formation?
With your partner, describe how different decomposers help to enrich soil. Classify soil organisms into two or more groups. You can decide how you will create your groups.

15. What is the role of plants and animals in soil formation?
Some organisms make humus; other organisms mix the soil and make spaces in it for air and water.