Your SlideShare is downloading. ×
Section ii and iii
Upcoming SlideShare
Loading in...5

Thanks for flagging this SlideShare!

Oops! An error has occurred.


Saving this for later?

Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime - even offline.

Text the download link to your phone

Standard text messaging rates apply

Section ii and iii


Published on

Published in: Education, Technology

  • Be the first to comment

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide


  • 1. Section II The Nature Of Soil
  • 2. Formation of soil
    • can take thousands of years
  • 3. Soil
    • is a mixture of weathered rock, decayed organic matter, mineral fragments, water, and air
  • 4.
    • formation is influenced by climate, slope, type of rock, types of vegetation, and length of time that the rock has been weathering
  • 5. Composition of soil
    • the ingredients that make up soil
  • 6.
    • 1. clay, silt, and sand are small particles of sediment
    • 2. decaying, dark-colored plant and animal material is called humus
    • 3. small spaces between soil particles may be filled with air or water
  • 7. Soil profile
    • made up of different layers of soil
  • 8. Horizon O
    • top layer of vegetation and organic matter
  • 9. 1. Horizon A – top layer of soil
    • May be covered with organic litter that may turn into humus
    • Fertile layer with more humus and less rock and mineral particles than other soil horizons
  • 10. 2. Horizon B – middle soil layer
    • contains less humus and is lighter in color than A horizon
  • 11.
    • minerals travel from horizon A to B horizon in a process called leaching
  • 12. Horizon C – bottom soil layer
    • has very little organic matter and is not strongly affected by leaching
  • 13.
    • Contains rock – the parent material from the soil
    • Glaciers can deposit soil that did not form from the bedrock beneath it
  • 14. Soil types – differ in different places
  • 15. Different regions have different climates that affect soil development
  • 16. Parent rock affects soil formation and type of vegetation that grows in a region
  • 17.
    • Time affects soil development because the longer the weathering has occurred, the less the soil resembles parent rock
  • 18.
    • Soil on steep slopes develops poorly
  • 19. Section III
    • Soil Erosion
  • 20.
    • Soil erosion or loss is important because plants do not grow as well when topsoil is lost.
  • 21.
    • Causes and effects of soil erosion – many human activities disturb the natural balance between soil production and soil erosion.
  • 22. Agricultural Cultivation
    • increased farming removes the plant cover, leaving soils open to wind and water erosion.
  • 23. Forest Harvesting
    • Removes forest vegetation which increases erosion and particularly damages tropical rain forest soil
  • 24. 1984 2004
  • 25. Overgrazing
    • Results when animals graze until almost all ground cover disappears
  • 26. Excess Sediment
    • Can damage the environment when soil erosion is severe
  • 27. Preventing Soil Erosion
    • Soil must be protected / conserved
  • 28. Manage Crops
    • Farmers plant shelter belts of trees to break the force of the wind
  • 29.
    • Bare soil can be covered with decaying plants to hold soil in place
  • 30.
    • Farmers can graze animals on vegetation instead of plowing it under
  • 31.
    • With no-till farming, plant stalks are left in the field to provide cover for soil
  • 32. Reduce Erosion On Slopes
    • Contour farming reduces soil erosion by planting along the contours of slopes
  • 33.
    • Terracing creates steep-sided flat areas for crops on the sides of hills and mountains
  • 34. Reduce erosion of exposed soil
    • water sprayed onto bare soil to reduce wind erosion
  • 35.
    • Topsoil is replaced and trees are planted
  • 36.
    • Water flow can be controlled in strip mines
  • 37.
    • After mining, the land can be reclaimed