Soil survey area

Randolph County, Arkansas

Survey Area AR121• Arkansas
The short version

The most common soil here is Gepp, on about 24% of the land: a very gravelly silt loam, smooth, like flour. Captina and Doniphan come next.

About 58% of the land drains well, and 18% stays wet for long stretches; groundwater comes within two feet of the surface under 29% of it.

USDA rates 89% of the land very limited for a standard septic drain field, and 66% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 13% of the land floods occasionally or more, and bedrock lies within 40 inches under 11% of it.

Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.

The ground underfoot

The soils you're most likely standing on

The biggest named soils in Randolph County, Arkansas, each drawn five feet deep from its official USDA description, in its recorded colors.

Gepp
24% of the area
Very gravelly silt loam topsoil · well drained
Smooth, like flour. Fertile and holds water well.
Alfisols
Captina
10% of the area
Silt loam topsoil · moderately well drained
Smooth, like flour. Fertile and holds water well.
Ultisols
Doniphan
8% of the area
Very gravelly silt loam topsoil · well drained
Smooth, like flour. Fertile and holds water well.
Ultisols
Ventris
4% of the area
Cherty silt loam topsoil · moderately well drained
Smooth, like flour. Fertile and holds water well.
Alfisols
Loring
4% of the area
Silt loam topsoil · moderately well drained
Smooth, like flour. Fertile and holds water well.
Alfisols
Ashton
4% of the area
Silt loam topsoil · well drained
Smooth, like flour. Fertile and holds water well.
Alfisols

Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.

The biggest mapped areas

The dominant drainage class is Well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Randolph County, Arkansas. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Gepp very gravelly silt loam, 8 to 12 percent slopes 56K Well drainedDSomewhat limitedVery limited
Captina silt loam, 3 to 8 percent slopes 43K Moderately well drainedC/DVery limitedVery limited
Gepp-Doniphan association, rolling 31K Well drainedDVery limitedVery limited
Amagon silt loam 19K Poorly drainedC/DVery limitedVery limited
Gepp-Ventris association, rolling 18K Well drainedDVery limitedVery limited
Ashton silt loam, 0 to 1 percent slopes, occasionally flooded 18K Well drainedBVery limitedVery limited
Bosket fine sandy loam, 0 to 3 percent slopes 17K Well drainedBNot limitedVery limited
Hontas silt loam, 0 to 1 percent slopes, frequently flooded 14K Moderately well drainedCVery limitedVery limited
Peridge silt loam, 3 to 8 percent slopes 13K Well drainedBSomewhat limitedSomewhat limited
Ventris-Rock outcrop complex, 3 to 12 percent slopes 13K Moderately well drainedDVery limitedVery limited
Doniphan-Gepp association, undulating 13K Well drainedBNot limitedSomewhat limited
Kobel silty clay loam 13K Poorly drainedDVery limitedVery limited
Dundee silt loam, 0 to 1 percent slopes 13K Somewhat poorly drainedCVery limitedVery limited
Gepp very gravelly silt loam, 12 to 20 percent slopes 12K Well drainedDVery limitedVery limited
Doniphan gravelly silt loam, 8 to 12 percent slopes 12K Well drainedCSomewhat limitedVery limited
McCrory fine sandy loam, 0 to 1 percent slopes 11K Poorly drainedC/DVery limitedVery limited
Razort silt loam, 0 to 3 percent slopes, frequently flooded 10K Well drainedBVery limitedVery limited
Brocket gravelly fine sandy loam, 8 to 12 percent slopes 10K Well drainedBSomewhat limitedSomewhat limited
Loring silt loam, 8 to 12 percent slopes, west 10K Moderately well drainedC/DVery limitedVery limited
Gepp-Ventris association, steep 10K Well drainedDVery limitedVery limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Ultisols
Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.
Inceptisols
Young but developing soils found in mountains and river terraces. Variable properties — check drainage and bedrock depth.

What This Means

Building & Foundations

About 66% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 89% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.

Look Up a Specific Address

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