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Allamakee County Soil Data

Allamakee County, Iowa

USDA SSURGO / PHZM

Avg pH

6.5

Texture

Silt Loam

Drainage

N/A

Organic Matter

2.5%

Hydrologic Group

N/A

Data Story

About Soil in Allamakee County, Iowa

Balanced pH for Versatile Farming

Allamakee County maintains a pH of 6.45, aligning closely with the national median of 6.5 and slightly exceeding the state average. This balance creates a versatile environment for a wide range of Midwestern crops.

A Sandy-Silt Mix with Good Workability

A sandier profile of 25.3% blends with 54.9% silt and 19.0% clay. This higher sand content compared to neighbors improves workability and allows for easier root penetration for new plants.

Lower Organic Matter but High Resilience

Organic matter levels are lower here at 2.51% compared to the state average of 3.81%. However, the available water capacity of 0.200 in/in still beats the state average, providing good drought resilience for local growers.

Efficient Water Movement Through Porous Soils

Formal drainage and hydrologic group data are not available for this specific county dataset. The mix of over 25% sand suggests that water likely moves through these soils faster than in heavier clay regions.

Early Season Success in Zone 5a

Falling into Hardiness Zone 5a, Allamakee is perfect for short-season crops like peas and lettuce. Use the sandy-silt mix to your advantage by starting seeds early in the warming soil.

Soil Composition

Silt Loam
Sand: 25.3%
Silt: 54.9%
Clay: 19.0%
Silt Loam

Soil pH

6.5pH
6.45173998838549
Strongly AcidicSlightly AcidicNeutralSlightly AlkalineStrongly Alkaline
Ideal lawn range: 6.0 - 7.0

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Hydrologic group data not available.

Drainage Class

Drainage class data not available.

Soil Profile

Dominant texture: Silt Loam

O HorizonOrganic layer
0-2"
A HorizonTopsoil
2-10"
B HorizonSubsoil
10-30"
C HorizonParent material
30-60"
R HorizonBedrock
60"+

Typical soil profile. Actual depths vary by location.

Soil Amendment Products

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Frequently Asked Questions

What type of soil does Allamakee County have?

Allamakee County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 25% sand, 55% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Allamakee County's soil acidic or alkaline?

Allamakee County's soil has a pH of 6.5, which is moderately acidic. This range suits many crops and is common across much of the eastern US.

What is the drainage class for Allamakee County?

Drainage class data is not currently available for Allamakee County.

What crops or plants grow well in Allamakee County's soil?

Based on Allamakee County's Silt Loam texture, pH of 6.5, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.

What USDA soil order is found in Allamakee County?

The dominant USDA soil order for Allamakee County is not currently available in our dataset.

Soil & Planting Advisory: Allamakee County

Soil Verdict

Allamakee County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.

Planting Guidance

A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.

Soil Implications

Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.

Regional Context

Allamakee County closely matches the Iowa average hardiness conditions.

Other Counties in Iowa

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

Soil data sourced from USDA SSURGO via Soil Data Access. Data is informational only and should not be used as a substitute for on-site soil testing. Contact your local NRCS office for site-specific soil information.