Soils

Soils are the products of natural processes occurring on or near Earth’s surface. Water accumulation and movement, oxygen levels, plant and animal life, underlying rock types, and varying temperatures on rock materials determine the nature and quality of soils. Soils vary from place to place according to the materials and processes that form them. More than 180 soil series have been recognized in South Carolina. Soil associations have been named after the most common soil series occurring in a landscape. The Soil Conservation Service of South Carolina has divided the state into six land resource areas according to soil associations and topographic settings.

About two percent of South Carolina’s total land area is contained within the Blue Ridge Mountain region, which includes 387,000 acres in the northwest corner of the state. Acid-rich soils of the Blue Ridge are of a mesic temperature class. Most are naturally suitable for forestry and can become agriculturally prolific with the treatment of fertilizers and lime. Seventy percent of the area is forested with a mixture of oak-hickory and pine. Ten percent of the region is used for farming, primarily truck crops, hay, and corn.

Linking the Blue Ridge province to the Sandhills is the Piedmont. Extending westward from the fall line, the Piedmont area covers nearly seven million acres encompassing almost thirty-five percent of the state. Topography of the region is gently sloping to moderately steep with broad ridge tops and narrow stream valleys. Soils are of a thermic class and have suffered severe erosion due to years of farming. At least thirty percent of the region has been used for farming, while two-thirds is forested.

At the edge of the Piedmont, the Sandhills lie adjacent to the fall line in a belt five to thirty miles wide and covering more than two million acres of South Carolina. Soils have formed from unconsoli- dated sands and undergone slight to moderate erosion. Dry, sandy soils found in this region are strongly acidic and classified in a thermic family. Organic matter content and inherent fertility are low due to poor retention of water and plant nutrients. Two-thirds of the area is forested, with significant acreage in cash crops, predominantly cotton, corn, and soybeans.

Flanking the Sandhills, the coastal plain is a ten-to-forty-mile-wide belt encompassing nearly three million acres of South Carolina. Topography is slightly rolling near the Midlands, flattening to a nearly level coastline. Soils have developed from unconsolidated sands and clays and undergone slight to moderate erosion. Many soils in this region are poorly drained, although some well-drained soils occur along sandy slopes and ridges. Soils are strongly acidic and loamy in texture (moderately textured), underlain with slightly coarse clayey and sandy subsoils. Soils are of a thermic classification. Inherent fertility and organic matter content is moderate. The area, dominated by the state’s agricultural belt, is well suited for farming. About one-half is forested, with significant acreage of cash crops.

Spanning from the coastal plain to the seashore, the Atlantic coast flat-woods area is a thirty-to-seventy-mile-wide land strip encompassing more than six million acres. Meandering streams carve broad valleys through the virtually flat topography. Highest elevations are 125 feet above sea level. Four general soil groups are found in the flat-woods region: loamy, clayey soils of the wet lowlands; wet, sandy soils found in strips near the coast; well-mixed soils of river floodplains, underlain with sandy, loamy sediments; and clayey, sandy soils of coastal-area salt marshes and dunes. Most soils are strongly acidic. About two-thirds of the area is forested, with major farm crops and pastures occupying the remaining portion.

Craddoc, Garnet R., and C. M. Ellerbe. Land Resource Map of South Carolina. Clemson, S.C., 1966.

Ellerbe, Clarence. South Carolina Soils and Their Interpretations for Selected Uses. Columbia: South Carolina Land Resources Conservation Commission, 1974.

Kovacik, Charles F., and John J. Winberry. South Carolina: The Making of a Landscape. 1987. Reprint, Columbia: University of South Carolina Press, 1989.

Smith, Bill R., and D. C. Hallbrick. General Soil Map of South Carolina. Clemson: South Carolina Agricultural Experiment Station, 1979.

South Carolina Water Resources Commission. South Carolina Water Assessment. Columbia: by the author, 1983.