Ouachita County Soil Data
Ouachita County, Arkansas
Avg pH
5.2
Texture
Loamy sand
Drainage
Somewhat excessively drained
Organic Matter
1.6%
Hydrologic Group
A
Data Story
About Soil in Ouachita County, Arkansas
Sandy Entisols on the coastal plain
Ouachita County is dominated by Entisols, which are young soils with little profile development and an average pH of 5.16. This is significantly lower than the national median of 6.5, contributing to a soil score of 17.9. These acidic, undeveloped soils present unique challenges for traditional row-crop agriculture.
Loamy sand means rapid drainage
The soil is classified as loamy sand, containing a high 56.4% sand and only 11.7% clay. This texture is very easy to work with tools but offers poor nutrient retention because water moves through it so quickly. Silt accounts for 31.9% of the mix, providing just enough structure to keep the soil from being pure sand.
Low organic matter and water capacity
Organic matter is quite low at 1.58%, falling well behind the Arkansas state average of 4.15%. The available water capacity of 0.133 in/in is also below the state benchmark, meaning plants may stress quickly during dry spells. Successful growing requires frequent, light irrigation and regular additions of compost to build soil life.
Excessive drainage in Group A
This county belongs to Hydrologic Group A, characterized by high infiltration rates and low runoff potential. The soil is considered somewhat excessively drained, which is excellent for building foundations but difficult for moisture-loving plants. It is the opposite of the 'heavy' soils found elsewhere in the state, offering superior aeration for roots.
Zone 8a favors deep-rooted perennials
Hardiness Zone 8a allows for a long growing season that supports heat-loving crops like watermelons and sweet potatoes. Perennials with deep root systems, such as pine trees and certain fruit trees, are particularly well-suited for these sandy Entisols. With some supplemental nutrients, you can cultivate a thriving Southern landscape.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group A — Low Runoff
Sandy, well-drained soils with high infiltration rates. Water moves quickly through the soil profile. Lowest runoff potential when thoroughly wetted.
Drainage Class
Somewhat excessively drained
Water is removed rapidly. Soils may be droughty and have limited water-holding capacity.
Soil Profile
Dominant texture: Loamy sand
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Ouachita County have?
Ouachita County's soil is classified as Loamy sand. This indicates the relative proportions of sand, silt, and clay — 56% sand, 32% silt, and 12% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Ouachita County's soil acidic or alkaline?
Ouachita County's soil has a low pH of 5.2, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Ouachita County?
Ouachita County has a dominant drainage class of "Somewhat excessively drained." Moderate drainage allows adequate moisture retention while still permitting excess water to drain over time.
What crops or plants grow well in Ouachita County's soil?
Based on Ouachita County's Loamy sand texture, pH of 5.2, and Somewhat excessively drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.
What USDA soil order is found in Ouachita County?
Ouachita County's dominant soil order is Entisols. Entisols are recently formed soils with little to no horizon development. They are common on floodplains, steep slopes, and sandy deposits.
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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.