Sullivan County Soil Data
Sullivan County, Tennessee
Avg pH
5.2
Texture
Silty clay loam
Drainage
Well drained
Organic Matter
8.9%
Hydrologic Group
D
Data Story
About Soil in Sullivan County, Tennessee
Acidic Silty Clay Loams in the Highlands
Sullivan County is dominated by silty clay loam and young Inceptisols soil. The average pH of 5.17 is significantly more acidic than the national 6.5 median and falls below the Tennessee state average of 5.35.
Gritty Texture Meets Heavy Clay
This soil mix contains 35.6% sand and 16.0% clay, creating a grittier profile than many neighboring counties. While the 37.7% silt helps with structure, the higher sand content typically allows for faster initial drainage in garden beds.
Exceptional Organic Matter Levels
Sullivan County boasts an impressive 8.90% organic matter, nearly four times the state average of 2.44%. Despite this richness, the available water capacity of 0.153 in/in is lower than the state benchmark, meaning these soils may dry out faster than expected.
Fast Drainage but High Runoff Risk
The soil is classified as well-drained, but its hydrologic group D designation suggests a high runoff potential when the ground is saturated. This combination makes the land excellent for preventing root rot but challenging for managing storm water.
Acid-Loving Plants Thrive in Zone 7b
The high organic matter makes this a dream for specialized gardening in zone 7b. Blueberries and azaleas thrive in this acidic environment, and with a soil score of 45.8, your backyard crops are starting from a position of strength.
Soil Composition
Soil pH
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.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Silty clay loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Sullivan County have?
Sullivan County's soil is classified as Silty clay loam. This indicates the relative proportions of sand, silt, and clay — 36% sand, 38% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Sullivan County's soil acidic or alkaline?
Sullivan 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 Sullivan County?
Sullivan County has a dominant drainage class of "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 Sullivan County's soil?
Based on Sullivan County's Silty clay loam texture, pH of 5.2, and 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 Sullivan County?
Sullivan County's dominant soil order is Inceptisols. Inceptisols are young soils with weak horizon development. They occur in a wide range of climates and parent materials.
Planning your lawn? View lawn care data for Sullivan 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.