Clayton County Soil Data
Clayton County, Iowa
USDA SSURGO / PHZMAvg pH
6.4
Texture
Loam
Drainage
Poorly drained
Organic Matter
3.2%
Hydrologic Group
D
Data Story
About Soil in Clayton County, Iowa
Rich Prairie Mollisols
Clayton County features Mollisols, the gold standard of prairie soils, with an average pH of 6.41. This level is nearly identical to the state average, offering a neutral and highly productive environment for agriculture.
The Classic Loam Profile
The dominant texture is loam, created by a mix of 52.8% silt and 26.6% sand. This loamy profile is widely considered the best for farming due to its ideal balance of aeration and moisture retention.
Superior Water Storage
Organic matter sits at 3.16%, which is healthy but slightly lower than the 3.81% Iowa average. However, the available water capacity of 0.199 in/in is superior to the state benchmark, keeping plants hydrated through dry spells.
Slow Moving Water
This soil is categorized as poorly drained and falls into hydrologic group D. This means the ground stays wet longer than average, which benefits water-tolerant crops but may require drainage solutions for construction.
Endless Growing Potential
In zone 5a, the loamy soil supports everything from corn to leafy greens. Whether you are a hobbyist or a professional, these Mollisols offer a high-quality foundation for any agricultural project.
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: Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Clayton County have?
Clayton County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 27% sand, 53% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Clayton County's soil acidic or alkaline?
Clayton County's soil has a pH of 6.4, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Clayton County?
Clayton 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 Clayton County's soil?
Based on Clayton County's Loam texture, pH of 6.4, 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 Clayton County?
Clayton County's dominant soil order is Mollisols. Mollisols are fertile, dark-colored soils that formed under grassland vegetation. They are among the most productive agricultural soils in the world.
Soil & Planting Advisory: Clayton County
Soil Verdict
Clayton County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.
Planting Guidance
A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.
Soil Implications
Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Clayton County closely matches the Iowa average hardiness conditions. The zone range of 4b-5a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Clayton County on LawnByCounty.com →
Other Counties in Iowa
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.