Polk County Soil Data
Polk County, Tennessee
Avg pH
4.8
Texture
Loam
Drainage
N/A
Organic Matter
3.9%
Hydrologic Group
N/A
Data Story
About Soil in Polk County, Tennessee
Extreme Acidity in Polk
Polk County soil is exceptionally acidic with a pH of 4.79, well below the state average. This level is significantly more acidic than the national median of 6.5.
Sandy and Silty Texture
The soil contains 34.2% sand and 40.7% silt, making it lighter than many Tennessee clay soils. This texture facilitates good root penetration but may struggle with nutrient runoff.
Rich Organic Matter Content
With 3.93% organic matter, Polk far exceeds the state average of 2.44% and the national average of 2.0%. This high organic content is vital, as the water capacity is slightly lower than average at 0.152 in/in.
Drainage in High Acidity
The soil score of 34.6 reflects the challenges of high acidity on agricultural productivity. The sandy texture suggests rapid drainage, which can help prevent root rot in wet years.
Success for Acid-Loving Plants
Hardiness zone 7b and high acidity make Polk a paradise for blueberries and azaleas. Most traditional vegetables will require lime applications to thrive in these native soils.
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 Polk County have?
Polk County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 34% sand, 41% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Polk County's soil acidic or alkaline?
Polk County's soil has a low pH of 4.8, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Polk County?
Drainage class data is not currently available for Polk County.
What crops or plants grow well in Polk County's soil?
Based on Polk County's Loam texture, pH of 4.8, 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 Polk County?
The dominant USDA soil order for Polk County is not currently available in our dataset.
Planning your lawn? View lawn care data for Polk 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.