Marion County, Arkansas
The most common soil here is Moko, on about 13% of the land: a extremely flaggy clay loam, firm and a little sticky. Arkana and Clarksville come next.
About 78% of the land drains well; groundwater comes within two feet of the surface under 14% of it.
USDA rates 88% of the land very limited for a standard septic drain field, and 74% very limited for homes with basements. That means extra cost or special design, not that it can't be done.
Worth knowing: 3% of the land floods occasionally or more, and bedrock lies within 40 inches under 45% 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 soils you're most likely standing on
The biggest named soils in Marion County, Arkansas, each drawn five feet deep from its official USDA description, in its recorded colors.
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 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.
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 88% 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.