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McCurtain County Soil Data

McCurtain County, Oklahoma

USDA SSURGO / PHZM

Avg pH

5.5

Texture

Water

Drainage

N/A

Organic Matter

1.4%

Hydrologic Group

D

Data Story

About Soil in McCurtain County, Oklahoma

The Acidic Soils of the Southeast

McCurtain County's soil is notably acidic, with an average pH of 5.47, well below the state average of 6.06. This acidity is a hallmark of the southeastern Oklahoma landscape, where high rainfall leaches away alkaline minerals. It creates a specific niche that is perfect for timber and acid-loving flora.

A Gritty Clay Mix

The soil features 40.7% sand and 20.4% clay, balanced by 31.1% silt. This composition provides a firm structure that can hold nutrients well, though the acidity can sometimes limit their uptake. The sand content helps with initial water penetration, but the clay ensures it doesn't drain away too fast.

Average Water, Low Organic Matter

Organic matter levels sit at 1.39%, trailing the state average of 1.72%. However, the available water capacity of 0.144 in/in perfectly matches the Oklahoma state average. This means that despite lower organic levels, the soil remains a dependable source of moisture for forest and field.

Tight Soils and Runoff Concerns

Classified under Hydrologic Group D, the soil in McCurtain County is characterized by high runoff potential and slow internal drainage. In this high-rainfall region, this can lead to frequent saturated conditions in low-lying areas. Proper drainage planning is essential for any construction or intensive gardening project.

Timber and Berries in Zone 8a

The warm, humid climate of zone 8a combined with acidic soil makes McCurtain County the premier spot for Loblolly pines and blackberries. It is also an excellent environment for southern ornamentals like camellias. Plant an acid-loving garden today to embrace the unique character of the Oklahoma southeast.

Soil Composition

Water
Sand: 40.7%
Silt: 31.1%
Clay: 20.4%
Water

Soil pH

5.5pH
5.47011451760875
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

Group D — High Runoff

Clay soils with very slow infiltration rates. Highest runoff potential. These soils have a permanent high water table or are shallow over impervious material.

Runoff potential:High

Drainage Class

Drainage class data not available.

Soil Profile

Dominant texture: Water

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.

Acidic Soil Detected

Your county's average pH is 5.5. These products help balance soil pH for healthier grass.

Browse Soil Amendments

Frequently Asked Questions

What type of soil does McCurtain County have?

McCurtain County's soil is classified as Water. This indicates the relative proportions of sand, silt, and clay — 41% sand, 31% silt, and 20% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.

Is McCurtain County's soil acidic or alkaline?

McCurtain County's soil has a low pH of 5.5, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.

What is the drainage class for McCurtain County?

Drainage class data is not currently available for McCurtain County.

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

Based on McCurtain County's Water texture, pH of 5.5, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas.

What USDA soil order is found in McCurtain County?

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

Soil & Planting Advisory: McCurtain County

Soil Verdict

McCurtain County is in USDA hardiness zone 8a, a warm climate zone. where winter lows can reach 10°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.

Planting Guidance

Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. 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

Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.

Regional Context

McCurtain County is somewhat warmer than the Oklahoma statewide average. The zone range of 7b-8a within the county means soil and planting decisions should account for local elevation and topography.

Other Counties in Oklahoma

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.