1. Day 19 Objective You will learn about soil texture and composition in order to determine soil’s value as a resource and conservation measures. Warm-Up Think back to weathering and erosion, Why is soil important?

2. SOIL Notes

3. @%*! Your first dirty word for the day

4. @%*T

5. @I*T

6. @IRT

7. DIRT This is the stuff under your fingernails

8. Why is soil science intimidating? Whole new vocabulary Whole new vocabulary Hard to visualize Hard to visualize Somewhat complex topics like chemistry and physics Somewhat complex topics like chemistry and physics

9. What is soil? Several different ways to define soil Several different ways to define soil 1) Geologic definition: Loose surface of the earth as distinguished from solid bedrock (support of plant life not required). 2) Traditional definition: Material which nourishes and supports growing plants (includes rocks, water, organic material, air).

10. What is soil made of? Mineral Matter Mineral Matter Organic Matter Organic Matter Air Air Water Water Think of an example for each of these…

11. What is the function of soil? Plant medium Plant medium Recycling system for nutrients Recycling system for nutrients Animal home Animal home Engineering medium Engineering medium System for water supply and purification System for water supply and purification

12. The ability of soil to perform those functions is dependent upon: Soil Texture Soil Texture Soil Structure Soil Structure Soil Chemistry Soil Chemistry Soil Age Soil Age Site Factors (topography, water, etc) Site Factors (topography, water, etc)

14. Soil Formation Factors There are five main factors that influence soil formation processes. There are five main factors that influence soil formation processes. 1) Type of Parent Material 2) Climate 3) Topography 4) Biotic Components 5) Time

15. Soil Profile and Horizons Soil PROFILE (entire picture put together) Soil HORIZONS (individual layers)

16. Soil Texture Soil Texture is the relative proportion of the primary particles in the soil. Soil Texture is the relative proportion of the primary particles in the soil. Sand = 2mm – 0.05mm Sand = 2mm – 0.05mm Silt = 0.05mm – 0.002mm Silt = 0.05mm – 0.002mm Clay = < 0.002mm Clay = < 0.002mm

17. Soil Texture This proportion of sand, silt, and clay can be grouped into textural classes. This proportion of sand, silt, and clay can be grouped into textural classes. Soil texture has a great deal to do with many other soil characteristics. Soil texture has a great deal to do with many other soil characteristics.

18. Soil Texture Coarse textured soil – soil that has a higher proportion of larger particles. Sand, Loamy sand, Sandy loam. Coarse textured soil – soil that has a higher proportion of larger particles. Sand, Loamy sand, Sandy loam. Fine textured soil – soil that has a higher proportion of smaller particles. Clay, Silty clay, sandy clay. Fine textured soil – soil that has a higher proportion of smaller particles. Clay, Silty clay, sandy clay.

19. Soil Composition Finding Total Mass: Finding Total Mass: Sand +Silt+Clay= Total mass of Sample Example: Sample A: 17 g Sand; 13g Silt; 20g clay 17+13+20 17+13+20=50g

20. Soil Composition Finding Percentage: Finding Percentage: Particle Amount ÷ Total mass of Sample =answer X 100= % Example: Sample A: 17 g Sand; 13g Silt; 20g clay 13÷50g x100=17÷50g x100= 20÷50g x100=

21. Closure Explain the components of soil and determine the soil texture of a soil with 10% sand 30% silt and 60% clay