Sebastian County Soil Data

Sebastian County, Arkansas

Avg pH

5.7

Texture

Fine sandy loam

Drainage

Moderately well drained

Organic Matter

1.6%

Hydrologic Group

C

Data Story

About Soil in Sebastian County, Arkansas

Acidic Ultisols Define the Sebastian Landscape

Sebastian County features fine sandy loam from the Ultisol order, reflecting highly weathered, acidic conditions. The average pH of 5.69 sits well below the national median of 6.5, though it remains slightly less acidic than the state average of 5.56.

Balanced Sand and Silt for Easy Tilling

A mix of 40.8% sand and 43.2% silt creates a soil profile that is easy to work and manage. With only 16.0% clay, this soil offers decent aeration while maintaining enough structure to prevent rapid nutrient leaching.

Low Organic Matter with Solid Water Storage

The organic matter content of 1.63% trails the state average of 4.15%, indicating a need for consistent composting. Despite this, the available water capacity of 0.152 in/in exceeds the Arkansas benchmark, keeping plants hydrated during dry spells.

Moderately Drained Soils with Slow Infiltration

The county's soils are moderately well drained and belong to hydrologic group C. These characteristics imply a slow rate of water transmission, making surface runoff a primary concern during heavy storms.

Warm-Season Staples Flourish in Zone 8a

The long growing season in hardiness zone 8a is perfect for heat-loving crops like okra and sweet potatoes. Supplementing the native soil with organic material will yield the best results for home gardeners.

Soil Composition

Fine sandy loam
Sand: 40.8%
Silt: 43.2%
Clay: 16.0%
Fine sandy loam

Soil pH

5.7pH
5.68761728369049
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 C — Moderate-High Runoff

Soils with slow infiltration rates, often with a layer that impedes downward water movement. Higher clay content restricts drainage.

Runoff potential:Moderate-High

Drainage Class

Moderately well drained

Water is removed somewhat slowly. May have a slowly permeable layer or seasonal water table.

Soil Profile

Dominant texture: Fine sandy 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.

Frequently Asked Questions

What type of soil does Sebastian County have?

Sebastian County's soil is classified as Fine sandy loam. This indicates the relative proportions of sand, silt, and clay — 41% sand, 43% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Sebastian County's soil acidic or alkaline?

Sebastian County's soil has a pH of 5.7, which is moderately acidic. This range suits many crops and is common across much of the eastern US.

What is the drainage class for Sebastian County?

Sebastian County has a dominant drainage class of "Moderately well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.

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

Based on Sebastian County's Fine sandy loam texture, pH of 5.7, and Moderately well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.

What USDA soil order is found in Sebastian County?

Sebastian County's dominant soil order is Ultisols. Ultisols are highly weathered, clay-rich soils common in humid regions. They are low in natural fertility and often require lime and fertilizer for agriculture.

Other Counties in Arkansas

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.