1. SOIL

2. Decaying Organic Matter
Soil provides…
nutrients for plant growth.
Soil comes from:
Rocks
Minerals
Decaying Organic Matter

3. EROSION is the movement of sediment and rock to new places.

4. Weathering
is the breaking down of rocks to create soil. It can be caused by wind, water, ice, or living things

5. There are five components of soil:
1. Rock
2. Sand
3. Silt
4. Clay
5. Humus
Can you match each type of soil to its picture?

6. Rock is solid and made of minerals

7. Sand
Sand is tiny grains of worn down rock. It doesn’t hold water or have many nutrients.

8. Properties of Sand Color: white, tan, darker brown, an assortment
Texture: gritty, coarse
Capacity to retain water: water drains through sand quickly
Ability to support plants: sand is not a fertile soil

9. Sand ------------Silt---------------Clay
Silt is very small, broken pieces of rock. It is larger than clay, but smaller than sand. It is powdery when dry.
Sand Silt Clay
(larger particles) (smaller particles)

10. Properties of Silt Color: rich dark brown
Texture: larger than clay, but smaller than sand; smooth and slippery when wet
Capacity to retain water: retains water well
Ability to support plants: fertile for plants

11. Clay is used for adobe or brick houses.
Clay holds water well. It is sticky and can be shaped when it is wet. But, it is very hard when dry.
Clay has many nutrients.
Clay is used for adobe or brick houses.

12. Properties of Clay Color: shades of gray
Texture: sticky and plastic-like when wet; spreads into ribbons when squeezed; very fine texture
Capacity to retain water: holds too much water, becomes water-logged & drowns plants
Ability to support plants: not a fertile soil for plants

13. Humus
Humus is made of leaves, twigs, small animals, or other decayed substances.
Humus adds many nutrients to the soil.
Humus is in the topsoil.

14. Soil Particle Size
Note: clays are microscopic in size !

15. Formation of soils over time…
Youngest Layers
Oldest Layers

16. 4 Layers of Soil Undecayed Layer (The layer that contains the humus)
Youngest layers
4 Layers of Soil
Oldest layers
Undecayed Layer (The layer that contains the humus)
Topsoil (The layer on TOP)
Subsoil (The prefix SUB means under)
Bedrock (It’s hard as rock down there!)

17. Natural Resources Made by NATURE Cannot be replaced
Must be conserved (saved)! When soil is left without anything holding
it down, it can easily be
washed away by erosion!

18. Ways to Conserve Soil Plant trees Plant grass Healthy farming
Plant gardens to grow crops
What else can you do to conserve soil?
The plant’s roots hold the soil in place. This prevents water erosion!