What is Erosion?
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The movement of _______ by _________ or water to some new location.
Naturally a slow process but speeds up quickly when it is _____________
Billions of tons of exposed __________ are lost each year to erosion
Erosion History
 The invention of the ___________ greatly increased the amount of erosion by exposing large areas of farmland
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Early colonists would grow one crop _____________in the same place every year until the nutrients were used up and then they would move on leaving exposed soil behind.
Colonists moved west to the _______ ________ where the soil was rich in organic matter.
Farmland increased rapidly and by the 1930’s giant dust clouds of soil blew across the county due to dry exposed soil. _____________
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The government created the Soil conservation Service (SCS) (now the NRCS) within the Dept. of
_________________ to conserve the nation’s soils.
The NRCS maps and surveys soil to plan methods of soil conservation.
Modern technology has allowed the U.S. to increase its production allowing it to produce more food than needed.
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In the _________ the U.S. started growing grains for other countries adding to the erosion problem (dust storms in CA.)
Many conservation practices are still ignored when using large machinery because many practices are more difficult to do on a ___________ scale.
Besides farming, ______________________, _________________, overgrazing and some _________
___________________ all increase the rate of erosion
Types of erosion
 ____________– occurs on gentle slopes of exposed soil. Water creates small channels a few inches
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 deep. It may turn into gully erosion on steeper slopes.
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– Occurs on steep slopes. Fast moving water cuts deep ditches into the soil that can change the landscape.
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– gradual removal of topsoil by wind or water. Occurs in thin layers on very gentle to non-sloping exposed soils. It can be seen by blowing dust and muddy water.
____________ – Large movements of soil due to gravity (landslide in California)