2. SOIL A resource our world depends on

3. What is soil made from? Sand Small pieces of rock Water and air Humus (decaying plant or animal material)

4. Soil is important Food

5. Soil is important Fertile soil is in limited supply and takes a long time to form Is considered a nonrenewable resource

6. Soil is important Animal homes- worms, spiders, ants, moles, foxes, rabbits live in the soil Birds nests Reptiles lay eggs and some build nests

7. The Process of Soil Formation Topsoil Subsoil

8. Texture of Soil The texture of soil depends on the proportion of sand, silt, and clay

9. Loam Made up of about equal parts of clay, sand, and silt Best for growing most types of plants

10. Different kinds of soil Sandy-drains well Clay-heavy and sticky Chalky- pieces of limestone Peaty-lots of dead plant material, found in bogs, soaks up water like a sponge

11. Classification of Soil Climate – hot, wet/ cold, dry/moderate Most common plants – grassland soil/forest soil Soil composition – rocky, sandy, rich in clay Acidic or basic – An acidic substance changes blue litmus paper red. A basic substance changes red litmus paper blue.

13. Soil Damage and Loss The value of soil is reduced when soil loses its fertility. Topsoil can be lost due to erosion.

14. In the 1930s, a huge area of land in the US was plowed in order to grow wheat on it. Worst drought in history began to dry the land. Strong winds began blowing the soil away. The area of land became known as the Dust Bowl. Almost 865 million tons of soil were blown away in 1935 alone. Video from PBS Dust Bowl

15. Soil Conservation Contour plowing- plowing along the curves of a slope Conservation plowing- no-till plowing/leave dead crops in the ground Crop rotation – plant different crops in a field each year