GEOG 1220 Chapter 9: Week 9
29 Mar 2017
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Document Summary
World on the edge: chapter 3: eroding soils and expanding deserts. In april 2010 a dust storm started in the gobi desert and moved to north. Carolina taking millions of tons of china"s topsoil. As soon as soil erosion exceeds new soil formation there is falling soil fertility and land abandonment. Losing topsoil means losing organic matter in the soil and vegetation on the land (leads to more carbon in the atmosphere) Roughly 1/3rd of the world"s cropland is losing topsoil at an excessive rate, reducing the land"s inherent productivity: for each inch of topsoil lost, wheat and corn yield declines by 6% Desertification affects 25% of the earths" land area. Sand storms are the final phase in the desertification process. Overplowing and overgrazing threaten topsoil: plowing and prolonged drought culminated in the 1930"s dust bowl in the us. Today there are two giant dustbowls forming: one in northern and western china in mongolia.
