Arkansas has 70 USDA soil survey areas covering a wide range of landscapes and soil conditions. The most common soil order is Ultisols — strongly weathered soils with clay-enriched subsoils, common in warm humid climates, making up roughly 46% of surveyed soils. Alfisols — moderately leached forest soils with a clay-enriched subsoil account for another 28%.
In terms of drainage, 43% of Arkansas soils are classified as well drained. About 34% of soils have some form of poor drainage, which is important to consider for septic systems and foundations. Drainage class affects everything from septic system design to basement feasibility to garden planning. Use the survey area pages below to see drainage details for specific counties, or look up any address for an exact soil profile.
Ultisols
46% of surveyed soils
Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.
Alfisols
28% of surveyed soils
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Entisols
8% of surveyed soils
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.
Inceptisols
8% of surveyed soils
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.
Mollisols
4% of surveyed soils
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Vertisols
3% of surveyed soils
High-clay soils that shrink and swell dramatically. Fertile but challenging for foundations and septic systems.