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.
- 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
Show as a table
| 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% |

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.
Where Calhoun soil is found
Mapped acres
Calhoun is mapped in Arkansas, Louisiana, Missouri, Mississippi and Tennessee.
| 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
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 95.7% |
| Not rated | 4.3% |
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
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 0.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 97.2% |
| Very poorly drained | 0.0% |
| Not rated | 2.8% |
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) | 1.8% |
| A/D: D as is, A if drained | 0.0% |
| B/D: D as is, B if drained | 0.3% |
| C/D: D as is, C if drained | 93.7% |
| Not rated | 4.3% |
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.