Johnson County Soil Data
Johnson County, Tennessee
Avg pH
4.1
Texture
Loam
Drainage
N/A
Organic Matter
4.0%
Hydrologic Group
N/A
Data Story
About Soil in Johnson County, Tennessee
Extreme acidity in the mountains
Johnson County has an exceptionally low pH of 4.07, making it far more acidic than the state average of 5.35 and the national median of 6.5. This unique chemical profile likely stems from its high-elevation mountain environment and specific parent materials.
A sandy, coarse soil texture
This soil is notably sandy at 34.8%, paired with 31.3% silt and only 12.0% clay. The low clay content and high sand percentage create a loose, coarse texture that allows for rapid air and water movement.
High organic matter, low water storage
Organic matter is very high at 3.99%, well above the state average of 2.44%. However, the available water capacity is quite low at 0.122 in/in, as the sandy texture cannot hold moisture as effectively as silty lowlands.
Fast-moving mountain water
While official drainage classes are unlisted, the high sand and low clay percentages suggest very rapid drainage. This prevents waterlogging but means nutrients can leach away quickly during heavy rains.
Acid-loving plants for Zone 7a
The 7a climate and acidic soil are perfect for blueberries, rhododendrons, and azaleas. If you want to grow vegetables, you will need significant lime applications to neutralize the intense natural acidity.
Soil Composition
Soil pH
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
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 Loam. This indicates the relative proportions of sand, silt, and clay — 35% sand, 31% silt, and 12% 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 4.1, 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?
Drainage class data is not currently available for Johnson County.
What crops or plants grow well in Johnson County's soil?
Based on Johnson County's Loam texture, pH of 4.1, and drainage class, 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 Johnson County?
The dominant USDA soil order for Johnson County is not currently available in our dataset.
Planning your lawn? View lawn care data for Johnson County on LawnByCounty.com →
Other Counties in Tennessee
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.