SOIL EEOSION" IlSr THE SOUTH. 17 



nessee presents such a problem, and the State is endeavoring to solve 

 it by a study of the soil possibilities. The State geologist, working 

 with a trained forester and soil expert, is preparing to reforest a large 

 extent of country that has been injured through erosion. 



The natural reclamation of flood plains covered with sand follows 

 the prevention of wash from the hillsides. With the velocity of the 

 water from the hills checked, only the finer material will be carried in 

 suspension to the flood plain.. By the continual deposition of sflty 

 material oviBr the sand during times of flood, a soil which is weU 

 adapted to agriculture will gradually be built up. However, of all 

 lands injured by erosion, it is probably hardest to develop a produc- 

 tive soil over those areas that have been covered to some depth with 

 sand. 



ERODED SECTIONS IN THE SOUTH. 



Throughout the South erosion is probably worse than in other 

 sections of the country. In the Atlantic Coast States the worst type 

 is encountered in the Piedmont section. It is less marked in the 

 mountains, probably because agriculture is less extensively practiced. 

 Erosion is very marked in some of the States of the Mississippi Valley, 

 some of the worst eroded sections of the country occurring in the hills 

 of these States. It is probable that the climate has much to do with 

 the fact that erosion is so rapid in the South. The character of the 

 soil makes a marked difference in the rates of erosion under the same 

 climatic conditions. 



The heavy clay soils erode fairly rapidly, but passing from this 

 heavy clay soil to soils of lighter character, containing a larger per- 

 centage of sand, the erosion changes in character from the surface or 

 shoestring type, developing guUies with rounded edges, to gullies 

 with caving sides. These two forms of erosion are illustrated in 

 Plate III, figures 1 and 2. Any marked difference in the character 

 of the soil and subsoil has a great influence on the erosion, which is 

 apparently most rapid in silty soils or in soils having a thin layer 

 of clay at the surface and a substratum of sand or sandy soil, as shown 

 in Plate IV. 



The region in the South subject to erosion comprises sections of 

 a number of different soil provinces, the Piedmont Plateau, the 

 Appalachian Mountain and Plateau,^ the Atlantic and Gulf Coastal 

 Plain, and the Glacial and Loessial regions, the greater part falling 

 within the two first-named provinces. The Piedmont and Appala- 

 chian regions differ more in elevation than in character of soil. The 

 Piedmont region extends along the eastern foot of the Appalachian 

 Mountains through Virginia, central North Carolina, western South 



' Erosion In the Southern Appaltichlan IloKJon has boon dkcussod by Olonn, with spocial roforeuco to 

 the effect on stream flow. U. 8. fJool. 8ur. I'apor No. 72. 



