Johnson County Soil Data
Johnson County, Arkansas
Avg pH
5.4
Texture
Fine sandy loam
Drainage
Moderately well drained
Organic Matter
1.9%
Hydrologic Group
C
Data Story
About Soil in Johnson County, Arkansas
Strongly Acidic Ultisols
Johnson County features Ultisols with an average pH of 5.38, which is more acidic than the state average of 5.56 and the national 6.5 median. The landscape is dominated by fine sandy loam, a texture that balances physical grit with agricultural utility. This soil profile reflects millions of years of weathering in the Arkansas climate.
Sand-Dominant Loam Mix
Over half of the soil is composed of sand at 52.3%, with 33.3% silt and 14.3% clay. This high sand content ensures the soil is easy to till and warms up quickly in the spring sun. However, it also means nutrients can leach away more easily than in heavier clay-based soils.
Nutrient and Water Management
The organic matter level is 1.90%, falling below the state average of 4.15% but close to the national 2.0% average. Available water capacity stands at 0.132 in/in, which is slightly under the state benchmark of 0.148 in/in. Regular additions of compost can help this sandy soil hold more moisture and nutrients.
Moderately Well Drained Grounds
Soil here is generally moderately well drained and falls into hydrologic group C. This indicates that while water moves through the sandy surface easily, there may be slower-draining layers deeper down. It is a solid middle-ground for gardening and home construction projects.
A Versatile Zone 8a Climate
The Zone 8a climate combined with sandy loam makes Johnson County perfect for root vegetables like carrots and radishes. Peach trees also thrive in these well-aerated soils, which prevent root rot during wet springs. It is time to plant your orchard and watch it flourish in this welcoming environment.
Soil Composition
Soil pH
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.
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
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Johnson County have?
Johnson County's soil is classified as Fine sandy loam. This indicates the relative proportions of sand, silt, and clay — 52% sand, 33% silt, and 14% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Johnson County's soil acidic or alkaline?
Johnson County's soil has a low pH of 5.4, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Johnson County?
Johnson 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 Johnson County's soil?
Based on Johnson County's Fine sandy loam texture, pH of 5.4, and Moderately well drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Johnson County?
Johnson 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.
Planning your lawn? View lawn care data for Johnson County on LawnByCounty.com →
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.