Alabama Landscapes

The Valley and Ridge

Soils, Agriculture and Vegetation

Soils and Agriculture

Soils on the high ridges of the Valley and Ridge have developed on sandstone and some shale and are similar to those of the plateaus of the Cumberland Plateau.  Most soils, however, are developed on limestone and dolomite. Where the rocks are relatively pure (free of chert), the soils are red with silt-loam surface layer and clay subsurface.  Where chert is common in the bedrock (e.g. much of the Knox Group-Table 1), the soils are more gravelly, and often chert fragments can reach several feet in diameter in the subsoil (Figure VRS1).

Figure VRS 1.  Soil developed on dolomite, Hoover, Shelby County.  Note the large chert fragments. (Image © Mike Neilson)

Except for the ridges, which tend to be forested, most of the area is cleared.  Cotton and soybeans are the main crops, and pastureland is extensive (Figure VRS 2).

Figure VRS 2. Sod Farm on limestone soils, St. Clair County.  These soils are suitable for grass growing because they have higher calcium content, a result of the weathering of limestone and dolomite. (Image © Mike Neilson)

Vegetation

The Valley and Ridge shows the same distribution of forest types as the Cumberland Plateau: oak-pine forests on the ridges, oak-hickory in the valleys (Figures VRS3 and 4). Here, however, it is the forest of the valleys that has been largely cleared for agriculture.

Figure VRS3. Oak-pine forest, Lake Purdy, Shelby County. (Image © Mike Neilson)

Figure VRS4. Oak-hickory forest, Cahaba River, Bibb County. (Image © Mike Neilson)

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