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Soils PowerPoint Presentation

Soils

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Soils

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Presentation Transcript

  1. Soils

  2. Importance of Soils • Plants grow in soils • Plants convert solar energy into chemical energy and produce oxygen. • Soil provides nutrition to plants. • Soils serve as a water filter

  3. What is soil? • Soil is a mixture of: • Mineral Matter • Organic Matter • Pore Space

  4. Can we make more soil? • Nature is capable of making new soil • 500-1,000 years to make 1 new inch of topsoil in optimal conditions. • Rate of soil formation is determined by 5 factors.

  5. Parent Material • The mineral matter content of soil originates as some form of stone that is eventually broken down. • The original parent material impacts the characteristics of the soil.

  6. Climate • Temperature • Cold • Hot • Precipitation

  7. Life • Life forms that exist under the surface of the soil help begin the process of soil formation • Lichens (fungus/algae) • Mosses • Eventually conditions become favorable for seeds to germinate. • Eventually animals become a factor as well

  8. Topography • “Lay of the land” • Changes in slope and elevation. • Impacts availability of moisture. • Presence of moisture increases rate of soil formation.

  9. Time • Absolute Age • Actual years the soils has been developing • Relative Age • Stage of maturity of soil

  10. Parent Material • Rock that has decomposed in place • Material that has been deposited • Glacial Till (glaciers) • Aeolian (wind) • Alluvium (streams) • Colluvium (gravity) • Lacustrine (lakes)

  11. Physical Characteristics of Soil • Particle Size Analysis • Soil Particles • Sand • Silt • Clay

  12. Soil Textural Classes • Based on percentages of Sand, Silt, Clay

  13. Point of intersection indicates soil texture Textural Triangle % Clay % Silt % Sand

  14. 25% sand, 25% silt, 50% clay 75% sand, 15% silt, 10% clay 30% sand, 40% silt, 30% clay 15% sand, 15% silt, 70% clay 40% sand, 40% silt, 20% clay 50% sand, 20% silt, 30% clay 2% sand, 81% silt, 17% clay 47% sand, 47% silt, 6% clay 60% sand, 25% silt, 15% clay 10% sand, 60% silt, 30% clay Soil Texture by Particle Analysis