Knox County Soil Data
Knox County, Indiana
Avg pH
6.2
Texture
Silty clay
Drainage
Poorly drained
Organic Matter
3.5%
Hydrologic Group
D
Data Story
About Soil in Knox County, Indiana
Young Inceptisols Anchor the Wabash Valley
Knox County is dominated by Inceptisols, which are relatively young soils with early horizon development. The average pH of 6.20 is slightly more acidic than the national median but remains higher than the Indiana average of 6.08.
Heavy Silty Clay Requires Careful Handling
The soil contains 53.3% silt and 18.2% clay, creating a silty clay texture that feels smooth but heavy. This mix provides great structure for plant roots but can become dense and difficult to work when it is too wet or too dry.
Healthy Organic Matter Supports Local Farms
Organic matter levels sit at 3.54%, which is well above the national average of 2.0%. However, the available water capacity of 0.190 in/in is slightly lower than the state average, meaning crops may need more attention during summer dry spells.
Managing Poorly Drained Hydrologic Group D
This county is characterized as poorly drained and belongs to Hydrologic Group D, which has very low infiltration rates. Farmers often utilize tiling to manage excess water and prevent root rot in these heavy soils.
Warm Zone 6b Offers Longer Seasons
As one of the southern counties in Zone 6b, Knox County offers a longer growing season for melons and peppers. With a solid soil score of 69.2, your garden will thrive if you provide adequate drainage.
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
Poorly drained
Water is removed so slowly that the soil is wet at or near the surface much of the year. Drainage improvement usually needed.
Soil Profile
Dominant texture: Silty clay
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Knox County have?
Knox County's soil is classified as Silty clay. This indicates the relative proportions of sand, silt, and clay — 27% sand, 53% silt, and 18% clay. Clay soils retain water and nutrients but can have drainage challenges.
Is Knox County's soil acidic or alkaline?
Knox County's soil has a pH of 6.2, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Knox County?
Knox County has a dominant drainage class of "Poorly drained." Poorly drained soils retain water for extended periods, which can limit crop choices and may require tile drainage or raised beds.
What crops or plants grow well in Knox County's soil?
Based on Knox County's Silty clay texture, pH of 6.2, and Poorly drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, rice, cranberries, and other water-tolerant species.
What USDA soil order is found in Knox County?
Knox 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.
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Other Counties in Indiana
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.