1. Introduction To Soils

2. Soil and It’s Importance
Provides basic life needs
Food and Shelter
Very limited resource

3. What is Soil?
soil is the mineral and organic matter that supports plant growth on the earth's surface. It is a mixture of particles of rock, organic materials, living organisms, air and water.

4. Who depends on soil? farmers & ranchers
anyone needing food, clothing, building materials, minerals
construction trades (buildings, roads etc.)

5. The success of farmers determines the income of who?
entire community
merchants

6. Main Ideas in Land Evaluation
1. Texture
2. Depth
3. Slope
4. Erosion

7. 1. Texture Affects almost all properties of the soil
The amount of sand, silt and clay in a soil
Sand=largest, then silt, then clay
Determine by ribboning the soil

8. 1. Texture
Sand is looser and gritty
Silt feels floury
Clay is sticky

9. 1. How to determine Texture
COURSE=NO BALL
MODERATLY COURSE= 1” and gritty
MEDIUM = 1” and smooth
MODERATELY FINE = 1-2”
FINE = 2”

10. Depth Total thickness of material available for plant growth
Plants obtain water, nutrients and support from the root zone
Total Depth is determined from the point where the roots stop

11. Depth DEEP=40” MODERATLEY DEEP = 20-40” SHALLOW = 10-20”
VERY SHALLOW = -10”

12. Slope Slope refers to the steepness of the land surface
Affects soil use and management
As slope increases agriculture suitability decreases

13. How to measure Slope
Measured in percent
Rise or fall over 100 feet

14. How to measure Slope NEARLY LEVEL = 0-1% GENTLY SLOPING = 1-3%
MODERATELY SLOPING = 3-5%
STRONGLY SLOPING = 5-8%
STEEP = 8-15%
VERY STEEP = +15%

15. Erosion Causes loss of soil by water and wind
If one knows history of land can then do something to prevent more losses

16. Erosion Calculation One will be given original topsoil
To find current topsoil drag knife through top layer until it stops. This is the topsoil

17. Erosion Calculation
Divide the current topsoil by the original to give you what percent is left
Then subtract that from 100% and that gives you amount of erosion.

18. Erosion Levels NONE TO SLIGHT = 0-25% MODERATE = 25-75%
SEVERE = 75%+ with crossable gullies
VERY SEVERE = 75%+ with uncrossable gullies

19. What is Soil Management?
the science of the tillage, cropping practices, and treatment of a soil for the production of plants
good soil management results in better yields and lower cost per unit of production

20. A knowledge of soil management is helpful in what occupational areas?
crop production
livestock production
horticulture
engineering
forestry
soil scientist
soil conservationist