Iowa County Soil Data
Iowa County, Iowa
USDA SSURGO / PHZMAvg pH
6.3
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.4%
Hydrologic Group
N/A
Data Story
About Soil in Iowa County, Iowa
Acidic Silt-Heavy Foundations
Iowa County soils have an average pH of 6.26, which is lower than the national median of 6.5 and the state average of 6.43. Specific taxonomic classifications are not currently listed in the data. The overall soil score of 64.3 is below the state average, suggesting some limitations for certain crops.
Fine Texture with High Silt
The soil contains 56.6% silt and 23.0% clay, balanced by 20.3% sand. This composition creates a smooth texture that is prone to crusting if the surface is not protected. It holds nutrients well but requires careful management to prevent compaction from heavy machinery.
Steady Moisture in Lower-Organic Soils
Organic matter levels average 2.44%, which is lower than the Iowa average of 3.81%. However, the available water capacity of 0.189 in/in remains close to the state average. This indicates the soil is capable of supporting plant life through moderate dry periods despite lower nutrient stores.
Monitoring Water Movement and Drainage
Dominant drainage and hydrologic group data are not available for this county. Given the high silt content, the soil likely has moderate permeability but can become saturated during heavy Iowa springs. Proper drainage is key to ensuring healthy root systems in this environment.
Versatile Planting in Zone 5b
The 5b hardiness zone allows for a wide range of gardening options, from orchard fruits to summer vegetables. Because the soil is slightly acidic, it is well-suited for berries and many native flowering perennials. Adding organic compost will help boost the 2.44% organic matter and improve your garden's yield.
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: Silt Loam
Typical soil profile. Actual depths vary by location.
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Iowa County have?
Iowa County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 20% sand, 57% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Iowa County's soil acidic or alkaline?
Iowa County's soil has a pH of 6.3, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Iowa County?
Drainage class data is not currently available for Iowa County.
What crops or plants grow well in Iowa County's soil?
Based on Iowa County's Silt Loam texture, pH of 6.3, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Iowa County?
The dominant USDA soil order for Iowa County is not currently available in our dataset.
Soil & Planting Advisory: Iowa County
Soil Verdict
Iowa County is in USDA hardiness zone 5b, a cold climate zone. where winter lows can reach -15°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. Winter protection (mulch, burlap wraps) helps push the zone boundary for desired species. 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
Iowa County closely matches the Iowa average hardiness conditions. The zone range of 5a-5b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Iowa 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.