Soil series profile
Sumter soil series
Sumter is a well drained soil with a silty clay loam surface, mapped on 364,718 acres in 41 counties across 7 states. Hydrologic group C.
- Drainage class
- Well drained 98% of mapped acres
- Hydrologic group
- C 79% of mapped acres
- Typical topsoil pH
- 7.5 slightly alkaline · range 7.5–7.5
- Mapped area
- 365k acres in 41 counties, 7 states
Typical Sumter profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–6 in (Ap) | Silty clay loam | 7.5 | 31% | 9% | 1.5% |
| 6–31 in (Bk) | Silty clay | 7.9 | 46% | 6% | 1% |
| 31–80 in (Cr) | Bedrock | Not reported | Not reported | Not reported | 0% |
What this means
What Sumter soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Sumter soils is slightly alkaline: pH 7.5. Acid-loving plants such as blueberries and azaleas struggle without amended beds, and some trees and shrubs show iron chlorosis (yellow leaves with green veins).
Loamy topsoil (loam, silt loam and similar) covers 51% of mapped Sumter acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silty clay loam (50% of mapped Sumter acres).
>99% of mapped Sumter acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
On >99% 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 >99% of the acres in mapped Sumter soils very limited, 0% somewhat limited and 0% not limited.
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 Sumter soil is found
Mapped acres
Sumter is mapped in Alabama, Mississippi, Arkansas, Tennessee, Georgia, Oklahoma and Louisiana.
| County | Acres | Share of county land |
|---|---|---|
| Lowndes County, AL | 64,754 | 16.0% |
| Montgomery County, AL | 46,565 | 10.5% |
| Hale County, AL | 33,987 | 9.5% |
| Dallas County, AL | 20,271 | 3.8% |
| Perry County, AL | 19,534 | 4.8% |
| Greene County, AL | 17,954 | 5.3% |
| Noxubee County, MS | 17,406 | 4.0% |
| Marengo County, AL | 16,275 | 2.9% |
| Lowndes County, MS | 14,866 | 4.7% |
| Hempstead County, AR | 8,912 | 1.9% |
| Oktibbeha County, MS | 8,507 | 3.0% |
| Howard County, AR | 8,116 | 2.2% |
| Wilcox County, AL | 7,582 | 1.5% |
| Prentiss County, MS | 7,360 | 3.0% |
| Sevier County, AR | 7,324 | 2.0% |
| Jasper County, MS | 6,364 | 1.5% |
| Monroe County, MS | 5,994 | 1.3% |
| Pickens County, AL | 5,760 | 1.1% |
| Clark County, AR | 5,125 | 0.9% |
| Sumter County, AL | 4,489 | 0.9% |
| Clarke County, MS | 4,435 | 1.0% |
| McNairy County, TN | 4,424 | 1.2% |
| Clay County, MS | 4,304 | 1.7% |
| Little River County, AR | 3,896 | 1.1% |
| Macon County, AL | 3,353 | 1.0% |
| Lee County, MS | 3,055 | 1.1% |
| Newton County, MS | 2,985 | 0.9% |
| Russell County, AL | 2,170 | 0.6% |
| Choctaw County, AL | 1,918 | 0.4% |
| Kemper County, MS | 1,439 | 0.4% |
| Alcorn County, MS | 1,094 | 0.4% |
| Autauga County, AL | 938 | 0.3% |
| Wayne County, MS | 741 | 0.2% |
| Washington County, AL | 715 | 0.1% |
| Houston County, GA | 645 | 0.3% |
| McCurtain County, OK | 562 | 0.0% |
| Butler County, AL | 366 | 0.1% |
| Itawamba County, MS | 328 | 0.1% |
| Hardin County, TN | 147 | 0.0% |
| Macon County, GA | 50 | 0.0% |
| Grant Parish, LA | 6 | 0.0% |
Septic absorption fields
NRCS rating, share of Sumter acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 0.0% |
| Very limited | 99.6% |
| Not rated | 0.4% |
Drainage, water table and flooding
Share of Sumter 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 2–14% (median 6%).
- Topsoil organic matter
- Median 3.5%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 97.6% |
| Moderately well drained | 2.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
| Not rated | 0.4% |
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 | 78.9% |
| D: very slow infiltration (clayey, shallow or wet) | 20.7% |
| 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 | 0.4% |
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 Sumter (component kind "Series") in SSURGO: 364,718 acres.
- Method
- Shares are by mapped acres of Sumter components. The profile comes from the single largest Sumter component. Full methodology.