Soil series profile
Zahl soil series
Zahl is a well drained soil with a loam surface, mapped on 1,891,335 acres in 41 counties across 3 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 78% of mapped acres
- Typical topsoil pH
- 7.9 moderately alkaline · range 7.2–8.0
- Mapped area
- 1.9M acres in 41 counties, 3 states
Typical Zahl profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–5 in (A) | Loam | 7.9 | 24% | 45% | 2% |
| 5–22 in (Bk) | Clay loam | 8.1 | 28% | 34% | 1% |
| 22–79 in (C) | Clay loam | 7.9 | 28% | 32% | 0.5% |
What this means
What Zahl soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Zahl soils is moderately alkaline: pH 7.9 (most land between 7.2 and 8.0). 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 100% of mapped Zahl acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is loam (99% of mapped Zahl acres).
100% of mapped Zahl acres is moderately well to excessively drained, which suits most garden plants.
For lawns and yards
Most land is in hydrologic groups B and C, where rain soaks in at a moderate pace.
For a septic system
For conventional septic absorption fields, NRCS rates 43% of the acres in mapped Zahl soils very limited, 57% somewhat limited and 0% not limited.
Only a licensed site evaluation or perc test at the actual lot decides whether a system is allowed and which design.
Where Zahl soil is found
Mapped acres
Zahl is mapped in North Dakota, South Dakota and Montana.
| County | Acres | Share of county land |
|---|---|---|
| Mountrail County, ND | 221,038 | 18.8% |
| Divide County, ND | 155,469 | 18.9% |
| McKenzie County, ND | 143,183 | 8.1% |
| Williams County, ND | 135,686 | 10.2% |
| Stutsman County, ND | 119,036 | 8.4% |
| McLean County, ND | 116,633 | 8.7% |
| Logan County, ND | 109,334 | 17.6% |
| Kidder County, ND | 101,147 | 11.9% |
| Burke County, ND | 95,353 | 13.3% |
| Ward County, ND | 88,634 | 6.8% |
| McIntosh County, ND | 70,420 | 11.7% |
| Sheridan County, ND | 66,909 | 10.7% |
| McPherson County, SD | 64,326 | 8.9% |
| Burleigh County, ND | 57,826 | 5.6% |
| Faulk County, SD | 33,573 | 5.2% |
| Edmunds County, SD | 31,133 | 4.2% |
| Campbell County, SD | 30,428 | 6.4% |
| Wells County, ND | 29,476 | 3.6% |
| Mercer County, ND | 25,529 | 3.8% |
| Dickey County, ND | 23,341 | 3.2% |
| Glacier County, MT | 22,032 | 1.4% |
| Oliver County, ND | 20,408 | 4.4% |
| Emmons County, ND | 15,429 | 1.6% |
| Dunn County, ND | 14,587 | 1.1% |
| Roosevelt County, MT | 11,375 | 0.8% |
| LaMoure County, ND | 10,713 | 1.5% |
| Walworth County, SD | 9,950 | 2.2% |
| Richland County, MT | 9,593 | 0.7% |
| Sheridan County, MT | 9,525 | 0.9% |
| Morton County, ND | 8,956 | 0.7% |
| Brown County, SD | 8,295 | 0.8% |
| Potter County, SD | 8,126 | 1.5% |
| Spink County, SD | 6,196 | 0.6% |
| Daniels County, MT | 3,404 | 0.4% |
| McCone County, MT | 2,866 | 0.2% |
| McHenry County, ND | 2,791 | 0.2% |
| Pondera County, MT | 2,362 | 0.2% |
| Wibaux County, MT | 1,799 | 0.3% |
| Dawson County, MT | 1,774 | 0.1% |
| Toole County, MT | 1,600 | 0.1% |
| Foster County, ND | 1,079 | 0.3% |
Septic absorption fields
NRCS rating, share of Zahl acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 57.0% |
| Very limited | 43.0% |
Drainage, water table and flooding
Share of Zahl acres
- Depth to seasonal high water table
- None reported within about 6.5 feet (median where reported).
- Flooding
- Not mapped as flooding on most acres.
- Slope
- Typically 5–25% (median 12%).
- Topsoil organic matter
- Median 2%.
Drainage class
Show as a table
| Category | Share of acres |
|---|---|
| Excessively drained | 0.0% |
| Somewhat excessively drained | 0.0% |
| Well drained | 100.0% |
| Moderately well drained | 0.0% |
| Somewhat poorly drained | 0.0% |
| Poorly drained | 0.0% |
| Very poorly drained | 0.0% |
Hydrologic soil group
Show as a table
| Category | Share of acres |
|---|---|
| A: fast infiltration (mostly sandy or gravelly) | 0.0% |
| B: moderate infiltration | 77.5% |
| C: slow infiltration | 22.5% |
| 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% |
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 Zahl (component kind "Series") in SSURGO: 1,891,335 acres.
- Method
- Shares are by mapped acres of Zahl components. The profile comes from the single largest Zahl component. Full methodology.