oceans. It would require centuries for replacement of the 

 fertile top soils that are being washed or blown away in a 

 single generation. 



The question whether the United States is a permanent 

 country, first raised some 70 years ago, has been considered 

 fantastic. Recent measurements indicate that it is far from 

 fantastic is very real and practical and that one can 

 rationally assert that in another century this great American 

 granary may have become inadequate to support our popula- 

 tion if erosion is permitted to continue at the present rate of 



EXTENT OF EROSION IN THE UNITED STATES 



1492 



SOU PRESERVED 



1935 



TOPSOIIGONE 

 OR * CONE 



TO ? GONE OCCASIONAL 



GULLYING 



SOU PRESERVED 



<SEVERE TO MODERATE GUllYING> 



EACH BLOCK REPRESENTS 135 MILLION ACRES 

 Figure 29. 



increase. Already in some sections of the country once 

 cultivated lands have been reduced to sterility. 



A deep-rooted but utterly falacious American tradition is 

 that agriculture is inherently a permanent industry. As 

 waters are lost, the soil may be lost. "When the soil is 

 gone, men must go; and the process does not take long," said 

 Theodore Roosevelt. 8 Recent studies indicate that the 

 Sahara and Gobi Deserts were once occupied by prosperous 

 peoples. 



8 Eighth Annual Message, Dec. 8, 1908. 



3 



