SOIL EKOSIOI^ IN THE SOUTH. 19 



more of very loose, incoliereiit soil. These freezes and thaws are 

 often followed by heavy rams which sweep away this loose surface 

 layer. This process occurs repeatedly during the winter, and as a 

 result large quantities of surface soil are removed. This soil is not 

 protected from the action of winter rains hke the soils of more north- 

 erly climates, where the soil is frozen during practically the entire 

 winter, so that the rain can not remove the soil mantle. In addi- 

 tion, the precipitation in more northerly regions is largely in the 

 form of snow, which melts gradually in the spring and is absorbed 

 by the soil, instead of runnmg off over the surface. 



Terracing is practiced in the southern Piedmont region, and the 

 destruction of the soil is thus greatly reduced. Since the precipita- 

 tion is mainly in the form of rain, the soil must be made to absorb 

 as much as possible. This can be done only by employing terraces 

 and the other methods already described. Plate VI shows a well- 

 terraced field in Piedmont Georgia. 



One of the peculiar soil conditions encountered in many sections 

 and most conducive to destructive erosion is a surface layer of heavy 

 soil material, varjdng from 6 inches to several feet in thickness, 

 underlain by sandy material. Erosion on this type of soil produces 

 enormous gulches, 10 to 50 feet deep and several hundred feet wide, 

 sometimes extenchng for 1 or 2 miles. They begin in the hills adjoin- 

 ing the lowlands, and by constant undercutting and caving push well 

 back into the hills. They are very difficult to stop and often work 

 their way across roadways, farms, forests, and even building sites. 

 It is problematical whether the progress of these gulches can be 

 entirely checked in any profitable way. However, it may be greatly 

 retarded by contmuaUy dumping debris, brush, or other material into 

 the gully, by planting wild honeysuckle around the head and sides 

 and young pines or other trees in the mouth. Much soil material 

 will thus be retained and in time the eroded area may be reclaimed. 

 This type of gully is shown in Plate VII, figures 1 and 2. Sandy 

 phases of the Orangeburg and Cecil soils suffer from this type of 

 erosion most frequently. 



Similar erosion is encountered in western Temiessee and northern 

 Mississippi, but in a different type of soil. Here the most destruc- 

 tive erosion occurs in areas of silty soUs. While the destruction is 

 as groat and the devastation possibly more complete, the hope of 

 reclamation is not so remote. For one thing, the depth of the gulHos 

 does not generally exceed 15 foot, because more resistant material 

 is encountered at about this depth. The sides aro slightly less 

 abrupt and there is a better opportunity for the growth of wild 

 plants or ev(!n th(5 gradual rcjclainution by reforestation. 



Sonui of the lands have Ikhui stri})p('d of their natural growth of 

 timbcT by rapid erosion. PVequontly a surface layer of heavy soil, 

 1(WH tiian a foot thick, covers a subsoil of much lightoi" niai(M-ial, in 



