Soil series profile

Keithville soil series

Keithville is a moderately well drained soil with a very fine sandy loam surface, mapped on 166,423 acres in 13 counties across 2 states. Hydrologic group C.

#2199 by mapped area fine-silty Glossaquic Paleudalfs (Alfisols)

Drainage class: Moderately well drained
Hydrologic group: C
Typical topsoil pH: 4.8
Mapped area: 166k

Typical Keithville profile

Texture and pH by depth

Depth to scale. More strongly shaded layers hold more clay. Horizon names are the soil survey's (A = topsoil, B = subsoil, C = parent material).

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Typical Keithville horizons (representative values)
Depth	Texture	pH	Clay	Sand	Organic matter
0–3 in (A)	Very fine sandy loam	4.8	15%	62%	1.25%
3–11 in (E)	Very fine sandy loam	4.8	15%	62%	0.65%
11–22 in (Bt)	Clay loam	4.8	30%	28%	0.4%
22–28 in (Bt/E)	Clay loam	4.8	30%	28%	0.4%
28–51 in (2Bt/E)	Silty clay	4.8	45%	10%	0.25%
51–81 in (2Bt)	Silty clay	4.8	45%	10%	0.25%

Representative values from the most extensive Keithville map unit (Keithville very fine sandy loam, 1 to 5 percent slopes, survey area LA031). Other map units of this series vary within the series range.

Stock photo for illustration, not a sample of this soil series. Credit on the Sources & method page.

What this means

What Keithville soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Keithville soils is very strongly acidic: pH 4.8. 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 mapped Keithville acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is very fine sandy loam (92% of mapped Keithville acres).

99% of mapped Keithville acres is moderately well to excessively drained, which suits most garden plants.

For lawns and yards

On 95% 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 95% of the acres in mapped Keithville soils very limited, 0% somewhat limited and 0% not limited (6% 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.

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

Where Keithville soil is found

Mapped acres

Keithville is mapped in Louisiana and Texas.

Counties with the most mapped Keithville soil
County	Acres	Share of county land
De Soto Parish, LA	58,796	10.5%
Sabine Parish, LA	45,558	8.2%
Caddo Parish, LA	41,953	7.5%
Jackson Parish, LA	7,681	2.1%
Angelina County, TX	6,106	1.2%
Natchitoches Parish, LA	4,114	0.5%
Bossier Parish, LA	1,117	0.2%
Bienville Parish, LA	881	0.2%
Harrison County, TX	140	0.0%
LaSalle Parish, LA	53	0.0%
Panola County, TX	11	0.0%
Rapides Parish, LA	9	0.0%
Red River Parish, LA	5	0.0%

Septic absorption fields

NRCS rating, share of Keithville acres

Not limited 0%

Somewhat limited 0%

Very limited 95%

Not rated 6%

Septic tank absorption field rating across mapped Keithville acres. Scale 0 to 100% of mapped land.

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Septic tank absorption field rating across mapped Keithville acres.
Category	Share of acres
Not limited	0.0%
Somewhat limited	0.0%
Very limited	94.5%
Not rated	5.5%

Drainage, water table and flooding

Share of Keithville acres

Depth to seasonal high water table: About 2.5 feet (30 in) (median where reported).
Flooding: Not mapped as flooding on most acres.
Slope: Typically 3–3% (median 3%).
Topsoil organic matter: Median 1.2%.

Drainage class

Excessively drained 0%

Somewhat excessively drained 0%

Well drained 0%

Moderately well drained 99%

Somewhat poorly drained 0%

Poorly drained 0%

Very poorly drained 0%

Not rated 1%

Drainage class across mapped Keithville acres. Scale 0 to 100% of mapped land.

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Drainage class across mapped Keithville acres.
Category	Share of acres
Excessively drained	0.0%
Somewhat excessively drained	0.0%
Well drained	0.0%
Moderately well drained	98.8%
Somewhat poorly drained	0.0%
Poorly drained	0.0%
Very poorly drained	0.0%
Not rated	1.2%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%

B: moderate infiltration 0%

C: slow infiltration 95%

D: very slow infiltration (clayey, shallow or wet) 0%

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 0%

Not rated 5%

Hydrologic soil group across mapped Keithville acres. Scale 0 to 100% of mapped land.

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Hydrologic soil group across mapped Keithville acres.
Category	Share of acres
A: fast infiltration (mostly sandy or gravelly)	0.0%
B: moderate infiltration	0.0%
C: slow infiltration	94.6%
D: very slow infiltration (clayey, shallow or wet)	0.0%
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	5.4%

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 Keithville (component kind "Series") in SSURGO: 166,423 acres.
Method: Shares are by mapped acres of Keithville components. The profile comes from the single largest Keithville component. Full methodology.

Independent reference site. No government affiliation or endorsement.

Full narrative description: USDA Official Soil Series Description for Keithville.