5 billion tons of topsoil washed and blown away in the US
"It's been estimated that every year the United States loses about 4,000,000 acres of cropland (about the size of Connecticut) to erosion. This amounts to about 5 billion tons of topsoil in the U.S. alone. Worldwide, the annual loss is about 26 billion tons."
J. A. Schneider, “Environmental Investigations: Trouble in the Fields,” SUNY Oswego, 2003, http://www.oswego.edu/~schneidr/CHE300/envinv/EnvInv11.html. [verified 4/15/14]