Soil series profile
Mountainburg soil series
Mountainburg is a well drained soil with a stony fine sandy loam surface, mapped on 1,215,823 acres in 28 counties across 2 states. Hydrologic group D.
- Drainage class
- Well drained 93% of mapped acres
- Hydrologic group
- D 92% of mapped acres
- Typical topsoil pH
- 5.3 strongly acidic · range 5.3–5.3
- Mapped area
- 1.2M acres in 28 counties, 2 states
Typical Mountainburg profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–5 in (A) | Stony fine sandy loam | 5.3 | 12% | 63% | 2% |
| 5–9 in (E) | Very stony fine sandy loam | 5.3 | 12% | 68% | 1.1% |
| 9–16 in (Bt) | Very stony fine sandy loam | 5.0 | 19% | 61% | 1.1% |
| 16–26 in (R) | Bedrock | Not reported | Not reported | Not reported | Not reported |
What this means
What Mountainburg soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Mountainburg soils is strongly acidic: pH 5.3. Most vegetables and lawn grasses do best around 6.0 to 7.0, so lime is often needed; blueberries, azaleas and rhododendrons like it as it is.
Loamy topsoil (loam, silt loam and similar) covers 92% of mapped Mountainburg acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is stony fine sandy loam (43% of mapped Mountainburg acres).
93% of mapped Mountainburg acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On 92% of mapped acres, rain soaks in slowly (hydrologic groups C and D, including dual groups that are D until drained). Expect runoff and puddles after heavy rain: core-aerate compacted lawns and keep ground sloping away from foundations.
For a septic system
For conventional septic absorption fields, NRCS rates 92% of the acres in mapped Mountainburg soils very limited, 0% somewhat limited and 0% not limited (8% not rated, such as urban land, pits or water).
Where the soil is very limited (slow permeability, a high water table, flooding, shallow bedrock or steep slopes), alternative systems such as mound or sand-filter designs are common and cost more.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Mountainburg soil is found
Mapped acres
Mountainburg is mapped in Arkansas and Alabama.
| County | Acres | Share of county land |
|---|---|---|
| Pope County, AR | 143,253 | 27.7% |
| Johnson County, AR | 101,421 | 24.0% |
| Faulkner County, AR | 97,826 | 23.7% |
| Franklin County, AR | 95,633 | 24.6% |
| Conway County, AR | 87,848 | 24.9% |
| Sebastian County, AR | 74,287 | 21.7% |
| Madison County, AR | 56,825 | 10.6% |
| Logan County, AR | 55,754 | 12.3% |
| Newton County, AR | 53,634 | 10.2% |
| Cleburne County, AR | 53,141 | 14.9% |
| Van Buren County, AR | 50,253 | 11.0% |
| Crawford County, AR | 49,998 | 13.2% |
| Pulaski County, AR | 41,675 | 8.5% |
| White County, AR | 36,916 | 5.6% |
| Washington County, AR | 36,454 | 6.0% |
| Stone County, AR | 32,347 | 8.3% |
| Yell County, AR | 27,378 | 4.6% |
| Scott County, AR | 23,921 | 4.2% |
| Carroll County, AR | 21,678 | 5.4% |
| Searcy County, AR | 21,581 | 5.2% |
| Independence County, AR | 16,673 | 3.4% |
| Boone County, AR | 16,070 | 4.3% |
| Shelby County, AL | 8,457 | 2.0% |
| Jackson County, AR | 6,638 | 1.6% |
| Baxter County, AR | 2,067 | 0.6% |
| Benton County, AR | 1,810 | 0.3% |
| Perry County, AR | 1,441 | 0.4% |
| Lonoke County, AR | 846 | 0.2% |
Septic absorption fields
NRCS rating, share of Mountainburg acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 91.9% |
| Not rated | 8.1% |
Drainage, water table and flooding
Share of Mountainburg acres
- Depth to seasonal high water table
- About 2.0 feet (24 in) (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 5–30% (median 12%).
- Topsoil organic matter
- Median 1.8%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 93.4% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 6.6% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 0.0% |
| C: slow infiltration | 0.0% |
| D: very slow infiltration (clayey, shallow or wet) | 92.3% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.0% |
| C/D: D as is, C if drained | 0.0% |
| Not rated | 7.7% |
Sources & data dates
- Source
- USDA NRCS Soil Survey Geographic Database (SSURGO), queried through Soil Data Access. Public domain.
- Data date
- SSURGO as published on November 3, 2026 (most recent survey area update October 26, 2026). NRCS refreshes SSURGO each October.
- Scope
- All map unit components named Mountainburg (component kind "Series") in SSURGO: 1,215,823 acres.
- Method
- Shares are by mapped acres of Mountainburg components. The profile comes from the single largest Mountainburg component. Full methodology.