SOIL EROSION IN THE SOUTH. 17 
nossee 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 lulls checked, only the finer material will be carried in 
suspension to the flood plain. By the continual deposition of silty 
material over the sand during times of flood, a soil which is well 
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 gullies 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, 1 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 
1 Erosion in the Southern Appalachian Region has been discussed by Glenn, with special reference to 
the effect on stream flow. U. S. Geol. Sur. Paper No. 72. 
