Soil series profile
Coly soil series
Coly is a well drained soil with a silt loam surface, mapped on 1,969,805 acres in 63 counties across 3 states. Hydrologic group B.
- Drainage class
- Well drained 100% of mapped acres
- Hydrologic group
- B 100% of mapped acres
- Typical topsoil pH
- 7.3 neutral · range 7.3–7.9
- Mapped area
- 2.0M acres in 63 counties, 3 states
Typical Coly profile
Texture and pH by depth
Show as a table
| Depth | Texture | pH | Clay | Sand | Organic matter |
|---|---|---|---|---|---|
| 0–5 in (A) | Silt loam | 7.9 | 22% | 14% | 2% |
| 5–10 in (AC) | Silt loam | 8.2 | 24% | 13% | 0.7% |
| 10–79 in (C) | Silt loam | 8.3 | 18% | 14% | 0.5% |
What this means
What Coly soil means for gardens, lawns and septic systems
For gardens
Typical topsoil in Coly soils is neutral: pH 7.3 (most land between 7.3 and 7.9), the range most vegetables, flowers and lawn grasses prefer.
Loamy topsoil (loam, silt loam and similar) covers 100% of mapped Coly acres: generally the easiest soil to garden, holding moisture without staying waterlogged. The most common surface texture is silt loam (100% of mapped Coly acres).
100% of mapped Coly 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 66% of the acres in mapped Coly soils very limited, 34% 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 Coly soil is found
Mapped acres
Coly is mapped in Nebraska, Kansas and South Dakota. The 60 counties with the most Coly acres:
| County | Acres | Share of county land |
|---|---|---|
| Custer County, NE | 300,844 | 18.3% |
| Lincoln County, NE | 203,325 | 12.4% |
| Frontier County, NE | 181,444 | 29.1% |
| Buffalo County, NE | 141,386 | 23.1% |
| Red Willow County, NE | 97,656 | 21.3% |
| Furnas County, NE | 97,050 | 21.1% |
| Dawson County, NE | 93,217 | 14.5% |
| Decatur County, KS | 90,965 | 15.9% |
| Valley County, NE | 72,767 | 20.1% |
| Sherman County, NE | 70,275 | 19.5% |
| Gosper County, NE | 67,057 | 23.0% |
| Graham County, KS | 62,372 | 10.8% |
| Harlan County, NE | 59,877 | 16.9% |
| Howard County, NE | 43,205 | 11.9% |
| Norton County, KS | 42,750 | 7.6% |
| Greeley County, NE | 41,340 | 11.4% |
| Nance County, NE | 32,860 | 11.7% |
| Phelps County, NE | 30,774 | 8.9% |
| Franklin County, NE | 29,983 | 8.2% |
| Kearney County, NE | 26,731 | 8.1% |
| Ness County, KS | 23,573 | 3.4% |
| Webster County, NE | 23,008 | 6.3% |
| Kiowa County, KS | 22,027 | 4.8% |
| Polk County, NE | 18,975 | 6.8% |
| Adams County, NE | 13,675 | 3.8% |
| Trego County, KS | 11,755 | 2.0% |
| Garfield County, NE | 9,001 | 2.5% |
| Ford County, KS | 7,278 | 1.0% |
| Logan County, NE | 5,921 | 1.6% |
| Boone County, NE | 4,156 | 0.9% |
| Hamilton County, NE | 3,916 | 1.1% |
| Seward County, NE | 3,795 | 1.0% |
| Butler County, NE | 3,665 | 1.0% |
| Wheeler County, NE | 3,462 | 0.9% |
| Hodgeman County, KS | 3,368 | 0.6% |
| Edwards County, KS | 3,294 | 0.8% |
| Loup County, NE | 2,903 | 0.8% |
| Hall County, NE | 2,562 | 0.7% |
| Smith County, KS | 2,388 | 0.4% |
| Gray County, KS | 2,153 | 0.4% |
| Gregory County, SD | 2,139 | 0.3% |
| Finney County, KS | 1,940 | 0.2% |
| Sheridan County, KS | 1,605 | 0.3% |
| Meade County, KS | 1,303 | 0.2% |
| Pawnee County, KS | 1,277 | 0.3% |
| Merrick County, NE | 1,002 | 0.3% |
| Republic County, KS | 904 | 0.2% |
| Rush County, KS | 633 | 0.1% |
| Phillips County, KS | 631 | 0.1% |
| Clark County, KS | 471 | 0.1% |
| Gove County, KS | 323 | 0.0% |
| Nuckolls County, NE | 219 | 0.1% |
| Barton County, KS | 169 | 0.0% |
| Haskell County, KS | 145 | 0.0% |
| Lane County, KS | 90 | 0.0% |
| Comanche County, KS | 83 | 0.0% |
| Clay County, NE | 53 | 0.0% |
| Hayes County, NE | 17 | 0.0% |
| Jewell County, KS | 17 | 0.0% |
| Kearny County, KS | 10 | 0.0% |
Septic absorption fields
NRCS rating, share of Coly acres
Show as a table
| Category | Share of acres |
|---|---|
| Not limited | 0.0% |
| Somewhat limited | 33.9% |
| Very limited | 66.1% |
Drainage, water table and flooding
Share of Coly 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 7–30% (median 18%).
- 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 | 100.0% |
| C: slow infiltration | 0.0% |
| 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 Coly (component kind "Series") in SSURGO: 1,969,805 acres.
- Method
- Shares are by mapped acres of Coly components. The profile comes from the single largest Coly component. Full methodology.