All About Soil

1. All About Soil All About Soil

2. Why Is Soil Important? Soil is Essential in the Hydrologic, Carbon, and Nutrient Cycles.

4. How Is Soil Formed?

5. There are four basic parts of soil: • Minerals (weathered rock) • Water • Air spaces • Organic material

6. Soil Properties • Texture- the particle size of minerals in soil • Structure- • Friability- ability to crumble • Porosity- measure of spaces in soil • Permeability- a measure of a soil's or rock's ability to transmit a fluid, usually water

7. Very Shallow — surface is less than 10 inches from a layer that retards root development. • Shallow — Soil surface is 10 to 20 inches from a layer that retards root development. • Moderately deep — Soil surface is 20 to 36 inches from a layer that retards root development. • Deep — Soil surface is 36 to 60 inches from a layer that retards root development. • Very deep — Soil surface is 60 inches or more from a layer that retards root development. Soil Properties • Shrink-swell potential- the potential for volume change in a soil with a loss or gain in moisture • pH- acidity/alkalinity • Slope- the stability of soil on a slope • Depth- • Color- indicates content of soil: red-iron; blue – anaerobic conditions; dark brown – high organic

9. Erosions • Splash- water hitting a surface such as rain • Sheet- surface runoff • Mass slippage- down slope movement of earth materials under the influence of gravity. • Rill- water concentrating in small, closely packed spaces and forms • Gully- steep-sided trenches formed by the coalescence of many rills

10. Soil can basically be separated into 5 main parts: • Humus • Clay • Silt • Sand • Gravel

11. Humus: A dark, moist soil composed of bits of dead, rotting insects, animals, leaves, roots, sticks, and food.  Humus adds nutrients to the soil which plants need to grow and live.

12. Clay: A soil that holds water.  When wet, clay feels slippery and slimy.  It is made of particles that are smaller than 0.004 millimeters.

13. Silt: Soil that looks like fine grains or tiny pieces of rock.  Particles classified as silt measure from 0.004 millimeters to 0.006 millimeters.

14. Sand: Soil that is coarse and drains quickly.  Sand particles measure from about 0.006 millimeters to 2.00 millimeters.

15. Gravel: Visible rock particles, sometimes referred to as pebbles.

16. What is a Soil Profile? • A soil profile is a view of a cross section of soil.

17. Characteristics of the Soil Horizons • 0 Horizon-located on surface, mostly O.M. • A Horizon-Called Topsoil, good amounts of O.M. and minerals. • B Horizon- Known as Subsoil, Less O.M. • C Horizon- Mostly parent material, does little for plant growth.

18. What is soil texture • It is the relative sizes of the different soil particles.

19. The major Soil Texture Classes • Sand-largest particle • Silt-medium size particle • Clay-smallest particle

20. Characteristics of aSandy Soil

21. Characteristics of a Silty Soil

22. Characteristics of a Clay Soil

23. Using the Soil Texture Triangle

24. What is Soil Structure? • Sand, silt and clay particles combine with one anther to form cluster calledaggregates. • The way in which aggregates or clusters are arranged is referred to as soil structure.

25. Soil Structure Categories

26. Wind Erosion

27. Suspension of dust by wind Fig. 13.2

28. Erg – a sea of sand Reg – desert pavement

29. Continued wind erosion results in desert pavement or “reg” in Arabic. Fig. 13.9

30. Desert Pavement