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237. Loss from water erosion. The damage done to soils 

 by erosion is very great. The soil is carried away, the fields 

 are cut into deep gullies, and often the owner of the soil 

 realizes too late that the best part of his soil has passed 

 entirely beyond his control (figs. 106 and 107). Obviously 

 regions with hilly topography are more subject to erosion 

 than level fields. Such fields will lose less of their soil if they 



FIG. 107. A late stage in erosion of deforested area 



The gullies have broadened until the whole of the original surface has been 



removed excepting where vegetation has protected it. Photograph by United 



States Forest Service 



are kept planted in grass, as pasture or meadow, or in timber. 

 (Why ?) In some places where hilly land must be cultivated 

 it is terraced around the hills in order to prevent erosion or 

 to catch any soil that may erode. 



The great importance of erosion of soils is suggested by 

 the fact that the Mississippi River is estimated to carry over 

 1,000,000 tons of sediment into the Gulf of Mexico every 

 day, or over 400,000,000 tons per year. Professor Salisbury 



