Soil survey area

Putnam County, Missouri

Survey Area MO171• Missouri
The short version

The most common soil here is Gara, on about 18% of the land: a loam, a balanced mix that crumbles in your hand. Winnegan and Armstrong come next.

About 21% of the land drains well, and 35% stays wet for long stretches; groundwater comes within two feet of the surface under 22% of it.

USDA rates 99% of the land very limited for a standard septic drain field, and 99% very limited for homes with basements. That means extra cost or special design, not that it can't be done.

Worth knowing: 16% of the land floods occasionally or more, and bedrock lies within 40 inches under 2% of it.

Soils change over short distances, so look up an address below for the soil at that exact spot and the reasons behind each rating.

The ground underfoot

The soils you're most likely standing on

The biggest named soils in Putnam County, Missouri, each drawn five feet deep from its official USDA description, in its recorded colors.

Gara
18% of the area
Loam topsoil · well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Winnegan
14% of the area
Loam topsoil · moderately well drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Armstrong
9% of the area
Loam topsoil · somewhat poorly drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Keswick
8% of the area
Loam topsoil · somewhat poorly drained
A balanced mix that crumbles in your hand. The gardener's ideal.
Alfisols
Nodaway
6% of the area
Silt loam topsoil · moderately well drained
Smooth, like flour. Fertile and holds water well.
Entisols
Adair
6% of the area
Clay loam topsoil · somewhat poorly drained
Firm and a little sticky. Holds water and nutrients well.
Alfisols

Dots mark gravel; white flecks mark lime. Shares are by acres across the survey area, and each mapped patch usually mixes several of these soils.

The biggest mapped areas

The dominant drainage class is Moderately well drained and the dominant hydrologic group is D (very slow infiltration, high runoff). The most common soil order is Alfisols — moderately leached forest soils with a clay-enriched subsoil. This report summarizes the major soil map units across the survey area to help you understand what to expect when buying, building, or gardening in Putnam County, Missouri. Search your address to find the exact soil composition, drainage, and series details at your specific location.

Soil Map UnitAcresDrainageHydro GroupDwellingsSeptic
Gara loam, 14 to 18 percent slopes, moderately eroded 51K Well drainedCVery limitedVery limited
Winnegan loam, 20 to 35 percent slopes 42K Moderately well drainedDVery limitedVery limited
Keswick loam, 5 to 14 percent slopes, eroded 26K Moderately well drainedDVery limitedVery limited
Armstrong clay loam, 5 to 9 percent slopes, moderately eroded 26K Somewhat poorly drainedDVery limitedVery limited
Adair loam, 3 to 9 percent slopes, eroded 22K Somewhat poorly drainedDVery limitedVery limited
Nodaway silt loam, 0 to 2 percent slopes, frequently flooded 17K Moderately well drainedBVery limitedVery limited
Vigar-Zook-Nodaway complex, 2 to 5 percent slopes 16K Moderately well drainedCVery limitedVery limited
Seymour silty clay loam, 2 to 5 percent slopes, moderately eroded 14K Somewhat poorly drainedDVery limitedVery limited
Shelby loam, 14 to 20 percent slopes, eroded 14K Moderately well drainedCVery limitedVery limited
Zook silty clay loam, 0 to 2 percent slopes, frequently flooded 12K Poorly drainedC/DVery limitedVery limited
Winnegan loam, 14 to 20 percent slopes, eroded 11K Moderately well drainedDVery limitedVery limited
Gara loam, 18 to 24 percent slopes, moderately eroded 11K Well drainedCVery limitedVery limited
Clarinda silty clay loam, 5 to 9 percent slopes, moderately eroded 9K Poorly drainedDVery limitedVery limited
Vanmeter silty clay loam, 14 to 30 percent slopes 8K Moderately well drainedDVery limitedVery limited
Pershing silty clay loam, 2 to 5 percent slopes 7K Moderately well drainedDVery limitedVery limited
Lamoni clay loam, 5 to 9 percent slopes, eroded 6K Somewhat poorly drainedC/DVery limitedVery limited
Colo silt loam, 0 to 2 percent slopes, frequently flooded 5K Poorly drainedC/DVery limitedVery limited
Gorin silt loam, 3 to 9 percent slopes, eroded 5K Somewhat poorly drainedCVery limitedVery limited
Schuline clay loam, 9 to 35 percent slopes 4K Well drainedCVery limitedVery limited
Armstrong clay loam, 9 to 14 percent slopes, moderately eroded 4K Somewhat poorly drainedDVery limitedVery limited

Soil Orders in This Area

The USDA classifies every soil into one of 12 soil orders. Here are the dominant orders found in this survey area.

Alfisols
Moderately weathered forest soils with clay-enriched subsoil. Productive for agriculture, generally good for building and septic.
Mollisols
Fertile grassland soils with thick, dark topsoil. Among the best for agriculture, building, and gardening.
Entisols
Young soils with little development — found on floodplains, dunes, and steep slopes. Properties vary widely by setting.

What This Means

Building & Foundations

About 99% of soils are rated "very limited" for dwellings with basements. Specific challenges include steep slopes, poor drainage in some areas, flood-prone areas. A geotechnical assessment is recommended before building.

Septic Systems

About 99% of soils are rated "very limited" for septic absorption fields. Despite good drainage overall, limitations may stem from shallow bedrock, steep slopes, or seasonal conditions. Engineered or alternative systems are frequently required. Always get a professional perc test before purchasing land that needs septic.

Gardening & Agriculture

Well-drained soils on sloped terrain — good for most plants but watch for erosion. Terracing, contour planting, and mulching help retain moisture and topsoil. Drip irrigation is more effective than sprinklers on slopes.

Look Up a Specific Address

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