1. The Ground Beneath Our Feet
S6E5. Students will investigate the scientific view of how the earth’s surface is formed.
h. Describe soil as consisting of weathered rocks and decomposed organic material.
i. Explain the effects of human activity on the erosion of the earth’s surface.
j. Describe methods for conserving natural resources such as water, soil, and air.

2. Directions
Read each slide. Some slides are just facts, look for the bold and underlined words to complete the notes

3. Precious Soil
You step on it. You stomp on it. You walk all over it. Soil doesn’t seem very precious. But it is. Without soil, which is a mixture of weathered rock and humus, there would be no plants. Without plants, we would have no food to eat and no oxygen to breathe. Soil is very precious to our way of living. Some people spend their entire careers studying soil.
Why don’t you give it a try?

4. Explain this quote after you complete the notes
“The nation that destroys
its soil, destroys itself.”

5. What Is Soil Made Of? Start Here (Copy on chart)

6. How is soil formed??? Soil is a MIXTURE of
weathered rock/mineral pieces
organic material (decayed plants and animals—thanks to fungus, lichen & bacteria)
(called HUMUS)
water and air
. It may take hundreds to thousands of years for one inch of soil to form.
soil is NONrenewable because it takes thousands of years to make

7. Read this: Soil begins to form when bedrock is broken apart into small pieces of minerals (rock). The agents rain, ice, wind, freezing, and thawing can do this breaking. Chemical changes can do this , too to rock.

8. continue reading: Plants and animals that live in small rock pieces help break apart rocks. As plant roots grow down, they pry apart rocks. Burrowing animals, such as earthworms and ants, create tunnels between rock pieces. Some of these tunnels fill with air and water. Water expands as it freezes, further breaking apart the rocks.

9. Read: How Soil Forms

10. Humus becomes mixed with the rock pieces
Humus becomes mixed with the rock pieces. Finally, a material that can be called soil is produced. Soil is a mixture of tiny rock particles, minerals, humus, water, and air. Soil takes a long time to form. It may take hundreds to thousands of years for one inch of soil to form. So it’s nonrenewable), so it needs to be protected (conserved)

11. Read ONLY
Bacteria and fungi also help create soil. They decompose dead plants and animals for energy. The leftover plant and animal matter is called humus.

12. SOIL Texture
Definition: the soil quality that is based on the proportions of soil particles.
Affects the soil’s consistency
The soil’s ability to be worked and broken up for farming
Influences infiltration
Ability of water to move through the soil
Also known as percolation
Largest particle
Smallest particle

13. Soil Properties: Soil Structure
Definition: the arrangement of soil particles
Often one type of soil particles will clump in one area, which can block the flow of water through the soil affecting soil moisture.

14. Soil Properties: Soil Fertility
Definition: Soil’s ability to hold nutrients and to supply nutrients to a plant
Soils vary in the amount of nutrients it contains. Plants need nutrients (such as IRON) to grow.

15. Soil Properties: Soil pH
Soils can be acidic or basic pH scale
Used to measure how acidic or basic a soil is and ranges from 0 to 14.
The midpoint 7 is neutral. Above 7= basic. Below 7= acidic.
The pH of a soil influences how nutrients dissolve in the soil.

16. Types of Soil
Sorted by their properties:
~Texture or size of particle
~Structure or arrangement of particle
~Fertility or ability to hold and supply nutrients
Loam is soil — best rich soil — that is a mix of sand, clay, and various organic materials.

17. Food for thought: Explain this cartoon!
What do you think…
Food for thought: Explain this cartoon!

18. The importance of soil
Soil provides minerals and other nutrients for plants.
All animals get their energy from plants, either by eating plants or by eating animals that have eaten plants.
Soil stores water for plant use
Soil also prevents water run off

19. Soil Forming Factors SOIL FORMING FACTORS
Soils develop as a result of the interplay of 5 factors; Parent material, climate, organisms, relief and time.
Parent material
SOIL FORMING FACTORS
Time
Climate
Relief (landforms and topography)
Organisms: vegetation, fauna and soil biota

20. Parent Material
This is the material from which the soil has developed and can vary from solid rock to deposits like alluvium and boulder clay. It has been defined as ‘the initial state of the soil system’.
Jenny H (1941) Factors of soil formation. McGraw- Hill Book Co Inc pp281.
The parent material can influence the soil in a number of ways:
color
texture
structure
mineral composition
permeability/drainage
This soil has developed on Old Red Sandstone and so has derived its distinctive color from its parent material.

21. Climate
This is probably the most important factor (soils produced from the same parent material under different climates contrast). Climate governs the rate and type of soil formation and is also the main determinant of vegetation distribution.
Soil climate has two major components; moisture (precipitation) and temperature, influencing evaporation. When precipitation exceeds evaporation, leaching of the soil will occur.
Temperature determines the rate of reactions; chemical and biological decay and so has an influence on weathering and humification.

22. Organisms : vegetation, fauna and soil microbes
Organisms influencing soil development range form microscopic bacteria to large animals including man. Micro organisms such as bacteria and fungi assist in the decomposition of plant litter. This litter is mixed into the soil by macro organisms (soil animals) such as worms and beetles.
Soil horizons are less distinct when there is much soil organism activity.
Higher plants influence the soil in many ways. The nature of the soil humus is determined by the vegetation cover and resultant litter inputs. Roots contribute dead roots to the soil, bind soil particles together and can redistribute and compress soil.

23. Relief (landforms and topography)
Relief is not static; it is a dynamic system (its study is called geomorphology). Relief influences soil formation in several ways:
It influences soil profile thickness i.e. as angle of slope increases so does the erosion hazard
it has an effect on climate which is also a soil forming factor
gradient affects run-off, percolation and mass movement
it influences aspect which creates microclimatic conditions
In this photograph soils are thin on the glacially eroded rock outcrops but are much deeper on the raised beach deposits in the foreground.

24. Time
Soils develop very slowly. In Britain it takes about 400 years for 10mm of soil to develop.
Young soils retain many of the characteristics of the parent material. Over time they acquire other features resulting from the addition of organic matter and the activity of organisms.
The soils of Britain are relatively young because they are largely post-glacial.
An important feature of soils is that they pass through a number of stages as they develop, resulting in a deep profile with many well differentiated horizons.
Recent soil
Buried soil
This soil profile shows a recent soil in Culbin Forest which has formed on sand overlying an ancient buried profile

25. Uses of soil: How do Humans (people) use the land (soil)?
Agriculture
Development-Construction of homes, stores, office buildings, etc.
Mining-Removal of iron, copper, and coal

26. Harm to Soil: Damage and loss
Soil can be damaged from overuse by poor farming techniques or by over grazing.
Deforestation: Cutting large masses of trees leaving bare forest land
Overuse– soil loses its nutrients
Overgrazing– animals eat (destroy) plants and leave the soil bare and exposed to erosion.

27. DEFORESTATION clear cutting the trees

28. DEFORESTATION clear cutting the trees

29. WHAT ABOUT THE ANIMALS? Where and how will they live?

30. pasture

31. pasture

32. Over grazing

33. Over grazing leads to ???

34. Overgrazing

35. SOIL POLLUTION chemicals being carried in water from field to river

36. Soil Movement: Erosion
Erosion is the process by which wind, water or gravity transport soil and sediment from one location to another.
Plant roots anchor the soil and keep it in place
By taking care of the plants you also take care of the soil.

37. EROSION

38. Leaching
Wherever rainfall exceeds evaporation and there is free downward movement of water through the soil pore system, soluble minerals are leached or removed from the soil profile.
Continual leaching tends to impoverish the upper mineral horizons by removal of basic cations (cations are ions having a a positive electrical charge e.g. Ca2+).
Leaching is most active in sandy soils with high porosity and is least in fine-textured soils such as clays which have restricted pore spaces.
A soil with small soil peds or crumbs and high porosity leading to free drainage and active leaching

39. DUST BOWL wind erosion
When you are finished with your notes go back to the soil food diner.
Select any Dust bowl link to help you answer the questions watch the video clips, and look at the images.

40. Predict three ways that soil can be conserved?
How do we SAVE OUR SOIL!
Predict three ways that soil can be conserved?