Marion County, Arkansas

Survey Area AR089• Arkansas

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 Ultisols — strongly weathered soils with clay-enriched subsoils, common in warm humid climates. 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 Marion County, Arkansas. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map Unit	Acres	Drainage	Hydro Group	Dwellings	Septic
Arkana-Moko complex, 20 to 40 percent slopes, very rocky	61K	Well drained	D	Very limited	Very limited
Estate-Portia-Moko association, 20 to 40 percent slopes, stony	60K	Well drained	C	Very limited	Very limited
Clarksville very gravelly silt loam, 20 to 50 percent slopes	53K	Somewhat excessively drained	B	Very limited	Very limited
Water	29K	Subaqueous		Not rated	Not rated
Estate-Portia-Moko association, 8 to 20 percent slopes, stony	21K	Well drained	C	Somewhat limited	Very limited
Arkana-Moko complex, 8 to 20 percent slopes, very rocky	20K	Well drained	D	Very limited	Very limited
Doniphan very gravelly silt loam, 8 to 20 percent slopes	20K	Well drained	C	Somewhat limited	Very limited
Nixa-Noark complex, 8 to 20 percent slopes	20K	Moderately well drained	D	Very limited	Very limited
Nixa very gravelly silt loam, 8 to 12 percent slopes	19K	Moderately well drained	D	Very limited	Very limited
Doniphan very gravelly silt loam, 3 to 8 percent slopes	15K	Well drained	C	Somewhat limited	Very limited
Nixa very gravelly silt loam, 3 to 8 percent slopes	11K	Moderately well drained	D	Very limited	Very limited
Gassville very gravelly silt loam, 20 to 40 percent slopes	10K	Well drained	D	Very limited	Very limited
Noark very gravelly silt loam, 20 to 40 percent slopes	8K	Well drained	C	Very limited	Very limited
Portia fine sandy loam, 8 to 12 percent slopes	8K	Well drained	B	Somewhat limited	Somewhat limited
Nixa-Noark complex, 3 to 8 percent slopes	7K	Moderately well drained	D	Very limited	Very limited
Noark very gravelly silt loam, 8 to 20 percent slopes	7K	Well drained	C	Very limited	Very limited
Razort silt loam, 0 to 3 percent slopes, frequently flooded	6K	Well drained	B	Very limited	Very limited
Portia fine sandy loam, 3 to 8 percent slopes	5K	Well drained	B	Not limited	Somewhat limited
Arkana-Moko complex, 3 to 8 percent slopes, very rocky	5K	Well drained	D	Very limited	Very limited
Arkana very gravelly silt loam, 3 to 8 percent slopes	5K	Well drained	D	Very limited	Very 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.

Ultisols

Strongly weathered clay soils of the Southeast. Acidic and naturally low in nutrients. Clay subsoil can slow drainage.

Alfisols

Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.

Mollisols

Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.

What This Means

Building & Foundations

About 74% of soils are rated "very limited" for dwellings with basements. Specific challenges include shallow bedrock, steep slopes, 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.