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Soil Erosion. Topic 2064 By: Carrie Vollmer. What is soil erosion?. Wind or water erosion is the physical wearing of the earth’s surface. Surface soil material is removed in the process. http://www.statlab.iastate.edu/soils/nssc/posters/carb_sld/sld002.htm.
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Soil Erosion Topic 2064 By: Carrie Vollmer
What is soil erosion? • Wind or water erosion is the physical wearing of the earth’s surface. • Surface soil material is removed in the process.
http://www.statlab.iastate.edu/soils/nssc/posters/carb_sld/sld002.htm
What happens if soil is eroded? • Poorer plant growth • Roots don’t have enough room • Less water, air and nutrients are available • Decrease soil organic matter • Lower rate of respiration and decomposition • Soil can accumulate in water • Cause algal blooms • Degrade water quality in streams, rivers and lakes • Fill drainage channels • Dust clouds
Soil Layers • O, A, B, and C • O is the top (organic) horizon • 1 inch thick • made of dead stuff • A horizon is topsoil • roots, tiny microbacteria, fungi and critters live/grow there • B is bedrock and very hard • Plants and animals have a tough time getting through • C is parent material • made of rock/soil that formed the 3 layers above http://www.nhq.nrcs.usda.gov/CCS/squirm/skworm.html
http://www.statlab.iastate.edu/soils/nssc/posters/carb_sld/sld002.htm
More than 300,000,000 acres out of our 400-odd million acres of farm fields are now eroding faster than soil is being formed. USDA NRCS AIB No. 99
How long does it take to make soil? • 1,000 years to form one-inch of soil • If people grew that slowly, it would take 80,000 years to grow a basketball player!
R = rainfall-runoff Intensity of rain over a period of time Amount of rain K = soil erodibility Susceptibility of soil Rate of runoff Whole soil LS = length and steepness of slope C = cover management factor Conservation plans Changes during the year P = support practice Ratio of soil loss with contour farming to straight row farming What 5 factors cause soil erosion?
Wind unsheltered soil surfaces high winds Machines removal of harvest tillage & cultivation Water steep slopes intense rainfall decreased infiltration minimal residue cover What really causes soil erosion? Soil Quality Resource Concerns: Soil Erosion April 1996
Water Erosion • Splash: raindrops hitting the ground • as high as 2 feet, horizontal splash up to 5 feet • Sheet:removal of soil from surface in thin layers and can go unnoticed • Rill: Shallow trenches, removed uniformly • Gully: narrow, deep soilless channels • 1-2 feet up to 75-100 feet
How can we prevent soil erosion? • Maintain a protective cover • winter cover crops, interseeding, no-till, filter strips • Create a barrier to the erosive agent • cultivate on the contour, stripcropping • Modify the landscape • shorten (length and height) of slopes, windbreaks
Soil conservation is the best way to make sure we have the land we need to live on. http://www.nhq.nrcs.usda.gov/CCS/squirm/skworm.html
http://www.nhq.nrcs.usda.gov/CCS/squirm/skworm.html http://www.statlab.iastate.edu/survey/SQI/sqiinfo.html