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Mahnomen County Soil Data

Mahnomen County, Minnesota

USDA SSURGO / PHZM

Avg pH

6.2

Texture

Loam

Drainage

N/A

Organic Matter

11.4%

Hydrologic Group

N/A

Data Story

About Soil in Mahnomen County, Minnesota

Ideally Balanced Native Soils

Mahnomen County boasts a near-perfect pH of 6.24, almost exactly matching the Minnesota state average of 6.21. This level is just slightly more acidic than the national median of 6.5, providing an ideal environment for most plants. It represents a highly versatile chemical baseline for diverse land use.

Sandy Loam Characteristics

The soil is relatively light, composed of 43.0% sand, 33.6% silt, and only 15.4% clay. This high sand content ensures excellent aeration and makes the ground very easy to till. However, the lower clay percentage means the soil relies heavily on its organic matter to hold onto nutrients.

High-Performing Organic Richness

Mahnomen surpasses state benchmarks with 11.38% organic matter, well above the state average of 9.90% and nearly six times the national average. This richness drives an available water capacity of 0.202 in/in, exceeding the state average of 0.199. These numbers explain the county's impressive soil score of 84.2.

Efficient Water Management

Though specific drainage classes aren't in the dataset, the 43.0% sand content typically indicates rapid water movement. This minimizes the risk of root rot and allows for earlier spring planting as the soil warms up quickly. The high water capacity ensures that even with fast drainage, moisture remains available to crops.

Lush Growth in Zone 4a

With a 4a hardiness rating, Mahnomen is perfect for sunflowers, small grains, and forest products. The high organic matter and ideal pH make it a dream for organic vegetable gardening. It is a highly productive environment for those willing to work with the cooler northern climate.

Soil Composition

Loam
Sand: 43.0%
Silt: 33.6%
Clay: 15.4%
Loam

Soil pH

6.2pH
6.2367120519328
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: 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 Mahnomen County have?

Mahnomen County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 43% sand, 34% silt, and 15% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Mahnomen County's soil acidic or alkaline?

Mahnomen County's soil has a pH of 6.2, which is moderately acidic. This range suits many crops and is common across much of the eastern US.

What is the drainage class for Mahnomen County?

Drainage class data is not currently available for Mahnomen County.

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

Based on Mahnomen County's Loam texture, pH of 6.2, 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 Mahnomen County?

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

Soil & Planting Advisory: Mahnomen County

Soil Verdict

Mahnomen County is in USDA hardiness zone 4a, a cold climate zone. where winter lows can reach -30°F. Soils here experience deep freeze cycles that can disrupt structure, kill shallow roots, and slow microbial activity for months each year.

Planting Guidance

Focus on cold-hardy perennials, native grasses, and conifers. The short growing window favors plants with low heat requirements. 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

Deep winter freezing can create soil heaving that pushes shallow-rooted plants out of the ground; add 3-4 inches of organic mulch each fall. Soil drainage is critical — frozen, waterlogged soil kills roots faster than cold alone. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.

Regional Context

Mahnomen County closely matches the Minnesota average hardiness conditions. The zone range of 3b-4a within the county means soil and planting decisions should account for local elevation and topography.

Other Counties in Minnesota

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.