County soil summary

Soil types in Sebastian County, Arkansas

The most widespread soils are Leadvale, Mountainburg and Enders; the most common drainage class is well drained (49% of the land), and typical topsoil pH is 5.3.

Mapped soil survey data 342,000 acres of mapped land · 23 named soil series

Well or moderately well drained
81%
of land · state 62%
Typical topsoil pH
5.3
strongly acidic · state 5.3
Septic fields very limited
94%
of land · state 86%
Subject to flooding
5%
of land, any frequency · state 17%

Most common soils in Sebastian County

Share of mapped land

A county is a patchwork of many soils. These 8 cover 86% of the mapped land; 23 named soil series are mapped here in all.

Most common soils in Sebastian County by share of mapped land
Soil Share of land Drainage Topsoil pH
Leadvale 22.1% Moderately well drained 5.0
Mountainburg 21.7% Well drained 5.3
Enders 17.9% Well drained 5.0
Taft 9.0% Somewhat poorly drained 5.3
Cane 5.1% Moderately well drained 6.1
Wrightsville 4.6% Poorly drained 4.6
Linker 2.9% Well drained 5.6
Sallisaw 2.5% Well drained 6.5

Drainage and pH for a series are its typical values across all its mapped acres nationwide. A dash means the row is not a soil series.

What this means

What the soils in Sebastian County mean for gardens, lawns and septic systems

For your garden

Typical topsoil in Sebastian County is strongly acidic: pH 5.3 (most land between 5.0 and 5.8). 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 95% of the land: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (44% of the land).

81% of the land is moderately well to excessively drained, which suits most garden plants.

For your lawn and yard

On 92% of the land, 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 94% of the land in Sebastian County very limited, 3% somewhat limited and 0% not limited (3% not rated, such as urban land, pits or water).

Statewide, 86% of the land is very limited, so Sebastian County is more restrictive than typical.

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.

Flooding is mapped on 5% of the land (2% occasional, 0% frequent).

Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.

Generated from the mapped numbers above using fixed rules, not a site visit. See how these notes are written.

Drainage

How long the soil stays wet

The most common drainage class is well drained (49%). 81% of the land is moderately well drained or better, compared with 62% across Arkansas.

Excessively drained 2%
Somewhat excessively drained 0%
Well drained 49%
Moderately well drained 30%
Somewhat poorly drained 9%
Poorly drained 8%
Very poorly drained 0%
Not rated 2%
Natural drainage class, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
Show as a table
Natural drainage class, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
Excessively drained1.6%1.0%
Somewhat excessively drained0.0%2.8%
Well drained49.0%41.3%
Moderately well drained30.0%16.8%
Somewhat poorly drained9.2%11.0%
Poorly drained7.8%21.8%
Very poorly drained0.0%0.3%
Not rated2.4%5.0%

Septic absorption fields

NRCS rating for conventional drain fields

The rating looks at the soil from 24 to 60 inches deep: permeability, depth to a seasonal water table or bedrock, flooding and slope. “Very limited” means at least one feature is unfavorable enough that a conventional field is hard to make work.

Not limited 0%
Somewhat limited 3%
Very limited 94%
Not rated 3%
Septic tank absorption field rating, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
Not limited0.0%0.0%
Somewhat limited3.3%6.0%
Very limited94.2%86.3%
Not rated2.5%7.8%

Rain, runoff and water table

Hydrologic soil group, flooding, seasonal water table

Hydrologic soil group

How fast rain soaks in when the soil is already wet. Group A soaks in fastest, D slowest.

A: fast infiltration (mostly sandy or gravelly) 3%
B: moderate infiltration 4%
C: slow infiltration 11%
D: very slow infiltration (clayey, shallow or wet) 50%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained 0%
C/D: D as is, C if drained 32%
Not rated <1%
Hydrologic soil group, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
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Hydrologic soil group, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
A: fast infiltration (mostly sandy or gravelly)2.8%2.6%
B: moderate infiltration4.0%15.3%
C: slow infiltration10.7%23.1%
D: very slow infiltration (clayey, shallow or wet)49.8%34.4%
A/D: D as is, A if drained0.0%0.1%
B/D: D as is, B if drained0.0%2.2%
C/D: D as is, C if drained31.9%16.0%
Not rated0.8%6.4%

Flooding

No flooding 90%
Rare or very rare 4%
Occasional 2%
Frequent or very frequent 0%
Not reported 5%
Most frequent flooding class in any month, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
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Most frequent flooding class in any month, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
No flooding90.2%73.5%
Rare or very rare3.5%4.1%
Occasional1.9%4.2%
Frequent or very frequent0.0%8.9%
Not reported4.5%9.2%

Seasonal high water table

Within 18 inches at some time of year 18%
18 inches to 3.3 feet 29%
Deeper than 3.3 feet or none reported 50%
Not reported 3%
Shallowest depth to a saturated zone in any month, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
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Shallowest depth to a saturated zone in any month, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
Within 18 inches at some time of year18.1%30.2%
18 inches to 3.3 feet28.9%17.8%
Deeper than 3.3 feet or none reported50.2%46.8%
Not reported2.8%5.2%

Topsoil pH and texture

First mineral layer of each soil

Typical topsoil pH is 5.3 (strongly acidic); 80% of rated land falls between 5.0 and 5.8. Median topsoil organic matter is 1.8%.

Strongly acidic (below 5.5) 81%
Moderately to slightly acidic (5.5–6.4) 10%
Near neutral (6.5–7.3) 5%
Alkaline (7.4 and up) 1%
Not reported 3%
Topsoil pH band, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
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Topsoil pH band, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
Strongly acidic (below 5.5)81.0%53.7%
Moderately to slightly acidic (5.5–6.4)10.3%28.8%
Near neutral (6.5–7.3)4.8%9.2%
Alkaline (7.4 and up)1.4%0.6%
Not reported2.5%7.8%

Texture

Sandy 2%
Loamy (loam, silt loam and similar) 95%
Clayey (40%+ clay) <1%
Organic (muck or peat) 0%
Not reported (rock, urban land, etc.) 3%
Topsoil texture group, share of mapped land in Sebastian County. Scale 0 to 100% of mapped land.
Show as a table
Topsoil texture group, share of mapped land in Sebastian County.
CategorySebastian CountyArkansas
Sandy1.6%3.3%
Loamy (loam, silt loam and similar)95.3%80.2%
Clayey (40%+ clay)0.6%8.7%
Organic (muck or peat)0.0%0.0%
Not reported (rock, urban land, etc.)2.5%7.8%

Most common surface textures: silt loam 44% · stony fine sandy loam 21% · stony sandy loam 8% · sandy loam 7% · fine sandy loam 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
Sebastian County, Arkansas (FIPS 05131): 341,597 acres of mapped land, 7,210 acres of open water excluded. State comparisons pool all mapped land in Arkansas.
Method
Shares are by mapped land area: each map unit’s acres in the county times each soil component’s percentage. Open water is excluded. Topsoil values use the first mineral horizon of each component. Full methodology.

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