Soil series profile

Calhoun soil series

Calhoun is a poorly drained soil with a silt loam surface, mapped on 729,470 acres in 60 counties across 5 states. Hydrologic group C/D.

#315 by mapped area fine-silty Typic Glossaqualfs (Alfisols)

Drainage class
Poorly drained
97% of mapped acres
Hydrologic group
C/D
94% of mapped acres
Typical topsoil pH
5.1
strongly acidic · range 4.8–5.5
Mapped area
729k
acres in 60 counties, 5 states

Typical Calhoun profile

Texture and pH by depth

Typical Calhoun soil profile by depth 0 in 20 in 40 in 60 in 0–3 in · Ap · pH 5.1 · 12% clay Silt loam 3–17 in · Eg · pH 5.3 · 16% clay Silt loam 17–30 in · Btg · pH 5.1 · 28% clay Silty clay loam 30–47 in · BCg · pH 5.3 · 18% clay Silt loam 47–79 in · Cg · pH 5.3 · 17% clay Silt loam
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 Calhoun horizons (representative values)
Depth Texture pH Clay Sand Organic matter
0–3 in (Ap) Silt loam 5.1 12% 4% 2.22%
3–17 in (Eg) Silt loam 5.3 16% 2% 0.99%
17–30 in (Btg) Silty clay loam 5.1 28% 2% 0.12%
30–47 in (BCg) Silt loam 5.3 18% 5% 0.1%
47–79 in (Cg) Silt loam 5.3 17% 6% 0.15%

Representative values from the most extensive Calhoun map unit (Calhoun silt loam, 0 to 1 percent slopes, survey area AR680). Other map units of this series vary within the series range.

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

What this means

What Calhoun soil means for gardens, lawns and septic systems

For gardens

Typical topsoil in Calhoun soils is strongly acidic: pH 5.1 (most land between 4.8 and 5.5). 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 96% of mapped Calhoun acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (96% of mapped Calhoun acres).

97% of mapped Calhoun acres is somewhat poorly to very poorly drained, so soil stays soggy for long spells after rain and in wet seasons. Raised beds, plants that tolerate wet feet, and not working the soil while wet all help.

For lawns and yards

On 96% 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.

A seasonal high water table comes within 18 inches of the surface on 97% of mapped acres, often in spring. Basements, sump pumps and lawns in low spots feel it first.

For a septic system

For conventional septic absorption fields, NRCS rates 96% of the acres in mapped Calhoun soils very limited, 0% somewhat limited and 0% not limited (4% 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.

Flooding is mapped on 20% of the acres (14% occasional, 2% 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.

Where Calhoun soil is found

Mapped acres

Calhoun is mapped in Arkansas, Louisiana, Missouri, Mississippi and Tennessee.

Counties with the most mapped Calhoun soil
County Acres Share of county land
West Carroll Parish, LA 83,276 36.4%
Butler County, MO 70,195 16.0%
Prairie County, AR 48,394 11.9%
Franklin Parish, LA 43,242 11.1%
Stoddard County, MO 39,943 8.0%
Monroe County, AR 36,920 9.5%
White County, AR 36,823 5.6%
Lonoke County, AR 30,470 6.3%
Craighead County, AR 24,286 5.4%
Avoyelles Parish, LA 23,115 4.4%
Jackson County, AR 22,366 5.5%
East Baton Rouge Parish, LA 20,577 7.1%
Greene County, AR 18,336 5.5%
Bollinger County, MO 18,105 4.6%
Evangeline Parish, LA 18,042 4.3%
Ashley County, AR 17,522 3.0%
Richland Parish, LA 16,610 4.7%
St. Landry Parish, LA 13,555 2.3%
Lawrence County, AR 12,174 3.3%
Catahoula Parish, LA 10,829 2.4%
Woodruff County, AR 10,207 2.7%
East Feliciana Parish, LA 8,819 3.1%
Ascension Parish, LA 8,112 4.4%
Livingston Parish, LA 6,985 1.7%
Drew County, AR 6,731 1.3%
Dunklin County, MO 6,588 2.0%
Lee County, AR 6,465 1.7%
Phillips County, AR 6,246 1.4%
St. Francis County, AR 5,752 1.4%
Wayne County, MO 5,169 1.1%
Ripley County, MO 5,108 1.3%
Madison County, TN 4,525 1.3%
Crockett County, TN 4,515 2.3%
Hinds County, MS 4,099 0.7%
Tallahatchie County, MS 3,917 1.0%
St. Helena Parish, LA 3,710 1.4%
Poinsett County, AR 3,440 0.7%
Madison County, MS 3,334 0.7%
Yazoo County, MS 3,106 0.6%
Benton County, MS 2,306 0.9%
Tangipahoa Parish, LA 2,154 0.4%
Clay County, AR 1,964 0.5%
West Feliciana Parish, LA 1,370 0.5%
Iberia Parish, LA 1,244 0.4%
Cross County, AR 1,134 0.3%
Pike County, MS 1,071 0.4%
Cape Girardeau County, MO 1,032 0.3%
Acadia Parish, LA 995 0.2%
Scott County, MO 907 0.4%
Lafayette Parish, LA 865 0.5%
St. Martin Parish, LA 508 0.1%
DeSoto County, MS 470 0.2%
Lincoln County, MS 376 0.1%
Lincoln County, AR 364 0.1%
Attala County, MS 362 0.1%
Copiah County, MS 328 0.1%
Franklin County, MS 243 0.1%
Jefferson County, AR 148 0.0%
New Madrid County, MO 20 0.0%
Pemiscot County, MO 1 0.0%

Septic absorption fields

NRCS rating, share of Calhoun acres

Not limited 0%
Somewhat limited 0%
Very limited 96%
Not rated 4%
Septic tank absorption field rating across mapped Calhoun acres. Scale 0 to 100% of mapped land.
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Septic tank absorption field rating across mapped Calhoun acres.
CategoryShare of acres
Not limited0.0%
Somewhat limited0.0%
Very limited95.7%
Not rated4.3%

Drainage, water table and flooding

Share of Calhoun acres

Depth to seasonal high water table
About 8 inches (median where reported); within 18 inches on 97% of acres.
Flooding
Mapped as flooding on 20% of acres (14% occasional, 2% frequent).
Slope
Typically 0–0% (median 0%).
Topsoil organic matter
Median 2.2%.

Drainage class

Excessively drained 0%
Somewhat excessively drained 0%
Well drained 0%
Moderately well drained 0%
Somewhat poorly drained 0%
Poorly drained 97%
Very poorly drained 0%
Not rated 3%
Drainage class across mapped Calhoun acres. Scale 0 to 100% of mapped land.
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Drainage class across mapped Calhoun acres.
CategoryShare of acres
Excessively drained0.0%
Somewhat excessively drained0.0%
Well drained0.0%
Moderately well drained0.0%
Somewhat poorly drained0.0%
Poorly drained97.2%
Very poorly drained0.0%
Not rated2.8%

Hydrologic soil group

A: fast infiltration (mostly sandy or gravelly) 0%
B: moderate infiltration 0%
C: slow infiltration 0%
D: very slow infiltration (clayey, shallow or wet) 2%
A/D: D as is, A if drained 0%
B/D: D as is, B if drained <1%
C/D: D as is, C if drained 94%
Not rated 4%
Hydrologic soil group across mapped Calhoun acres. Scale 0 to 100% of mapped land.
Show as a table
Hydrologic soil group across mapped Calhoun acres.
CategoryShare of acres
A: fast infiltration (mostly sandy or gravelly)0.0%
B: moderate infiltration0.0%
C: slow infiltration0.0%
D: very slow infiltration (clayey, shallow or wet)1.8%
A/D: D as is, A if drained0.0%
B/D: D as is, B if drained0.3%
C/D: D as is, C if drained93.7%
Not rated4.3%

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 Calhoun (component kind "Series") in SSURGO: 729,470 acres.
Method
Shares are by mapped acres of Calhoun components. The profile comes from the single largest Calhoun component. Full methodology.

Independent reference site. No government affiliation or endorsement.

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