1. Components and Properties of Soil

2. What is soil?
Material which nourishes and supports growing plants includes rocks, water, organic material and air.

3. How is soil formed? Rocks rubbing together for many, many years
Organic matter

4. What is our State……
Soil…..
Jory
Rock…..
Thunder Egg

5. What is the function of soil?
Plant medium
Recycling system for nutrients
Habitat for organisms
System for water supply
Water purification
Support foundation
Heat storage
Decomposes organic material
Buffer of toxic compounds to the environment
Source of raw materials
Gene pool
Source of history

6. Soil Formation - Parent Material
Parent Material is the “base” material that a soil is formed from.
To understand why soils are so variable, first consider the different types of materials that soils are formed from:
Primary parent materials:
Residual materials – north Georgia
Marine sediments – south Georgia
River Sediments throughout state along flood plains
Other materials:
Organic deposits – Okefenokee +
Wind – thought to be source of sand for certain deposits east of rivers
Gravity – down slope deposits in mountains
Soil
Soils are the product of the effects of climate, topography, and
living organisms acting on parent material over a period of time.

7. Soil Horizons
As soils develop by forming layers called Horizons.

8. O Horizon
Layer of accumulated organic matter such as leaves, grass, twigs
Material can be in various states of decomposition
Generally dark in color O A E B C R

9. A Horizon A Generally is the most productive horizon
High biological activity
Dark in color
Topsoil O A E B C R

10. E Horizon E Leached soil
Soluble minerals and organic material move out of this horizon
Lighter “washed” appearance in color O A E B C R

11. B Horizon
Less amount of parent material break down and organic matter.
More course fragments (rock visible)
Varies in color from reds and yellows to browns and grays O A E B C R

12. C Horizon
The unconsolidated material that has been affected little by the soil forming processes
Course fragments present O A E B C R

13. R Horizon R Hard bedrock 100% course fragments, also known as rock O A

15. Assignment You will make a “Soil Profile Flipbook”
Each horizon will be on a different flap
You must have the following:
Name of the horizon
Description and characterizes of the horizon
Color of the horizon
Soil profile
Make it colored

16. What is a soil Profile Review

17. Soil Differs in: Texture Color Structure Consistence
Fertility and Productivity

18. Soil Texture The way soil feels
Based on the relative proportions of each size of soil particle
Sandy loam, Silty loam, Sandy Clay loam
Soil texture is important because it influences many soil properties—drainage, water holding capacity, aeration, susceptibility to erosion, organic matter content, cation exchange capacity, pH buffering capacity, and soil tilth

19. Why is soil texture important?
Influences many soil properties
drainage, water holding capacity, aeration, susceptibility to erosion, organic matter content, cation exchange capacity, pH buffering capacity, and soil tilth

20. Soil Texture - Relative Sizes of Soil Particles
Sand ( mm)
Silt ( mm)
Clay (<0.002 mm)
Soil texture refers to the proportionate content of sand, silt, and clay fractions
Soil texture is an important soil property relating to infiltration, runoff, water holding capacity and nutrient availability
Topsoil texture is determined by the relative amounts of sand, silt, and clay particles in the topsoil. Sand particles are the largest and clay particles are the smallest. Silt particles are smaller than sand but larger than clay. At the contest, students will determine texture by feeling the topsoil. A sample of topsoil and water will be provided. In setting up the contest, the soil scientist will determine texture.
Soil Particle Size - The size of sand, silt and clay particles vary greatly in relation to each other. A grain of sand can be seen easily with the naked eye, while a clay particle can be seen only with a microscope. If a particle of sand were the size of a basketball, then a silt particle would be the size of a golf ball and a clay particle would be the size of a BB.

21. Sand Larger particles in the soil Can be seen with the naked eye
Not fertile
Quick to dry out and are doughy
Drain quickly

22. Silt Between sand and clay particles in size, medium size
Provide few nutrients to plants
Erode very easily
Moderate drainage

23. Clay Smallest of the soil particles Hold soil nutrients
Hold more moisture than either sand or silt
Dry out slowly
Become cloddy unless properly managed

24. What is loam? The Best of All Worlds
A soil type that contains all three particle sizes.
The most productive soil for farming crops
Has good water holding capacity (from clay)
Has good drainage (from sand)
Can be nutritious (from silt)
Good drainage is important so that air can reach root systems of plants

25. 12 Soil Texture Classes Sand (S) Loamy Sand (LS) Sandy Loam (SL)
Loam (L)
Silt Loam (SIL)
Silt (SI)
Sandy Clay Loam (SCL)
Silty Clay Loam (SICL)
Clay Loam (CL)
Sandy Clay (SC)
Silty Clay (SIC)
Clay (C)
The 12 soil texture classes have varying proportions of sand, silt, and clay. What is loam!!?? See next slide
Compositions of each of the 12 texture classes is defined by the USDA Soil Triangle

26. Soil Texture
Soil texture refers to the proportionate content of sand, silt, and clay fractions.
For the FFA contest, soils are categorized into fine, medium, or coarse
Fine - A fine textured soil is smooth and sticky when wet. When balled in the palm of your hand, it holds its shape and shows finger marks. A long ribbon of soil can be formed by rubbing the soil between the thumb and fore finger.
Medium - A medium textured soil is a mixture of sand, silt and clay particles. It is between fine and coarse. The ball will show some finger marks and hold its shape. A short thick ribbon can be formed.
Coarse - Coarse textured soils are made up of mostly sand particles. Sand feels gritty and particles are large enough to be easily seen. The ball breaks in your hand and almost no ribbon can be formed.
Refer to the textural flow chart in the FFA Land Judging Manual to assist in textural classification.

27. Soil Triangle http://www.youtube.com/watch?v=VEgHmgnrWzk
Take notes on what is being said

28. Soil Triangle Problems

29. Using the Soil Triangle find the following soils:
Has to equal 100% at the end!!
Sand: 75%
Silt: 10%
Clay: 15%
Sand: 10%
Silt: 83%
Clay: 7%
Sand: 20%
Clay: 70%
Clay
Sandy Loam
Silt

30. Worksheet on your own