Benton County Soil Data
Benton County, Iowa
USDA SSURGO / PHZMAvg pH
6.3
Texture
Loam
Drainage
Well drained
Organic Matter
3.5%
Hydrologic Group
B
Data Story
About Soil in Benton County, Iowa
Woodland-Derived Alfisols in Benton
Benton County soil is categorized as Alfisols, with a pH of 6.30 that sits below the Iowa average of 6.43. These soils typically form under forest cover and are known for distinct sub-surface clay accumulation.
The Ideal Loamy Texture
The dominant texture is loam, featuring a balanced mix of 28.4% sand, 50.8% silt, and 20.1% clay. This balanced texture makes the soil exceptionally easy to work for both farmers and backyard gardeners.
High Organic Matter and Drainage
Organic matter is strong at 3.45%, though it trails the state average of 3.81%. The available water capacity of 0.182 in/in is slightly lower than the state average, meaning consistent watering is key during dry weeks.
Excellent Drainage for Solid Foundations
This soil is well drained and belongs to hydrologic group B. This group indicates a moderate infiltration rate, making it an excellent choice for building foundations and garden drainage alike.
Deep-Rooted Favorites for Zone 5a
Zone 5a conditions are ideal for cool-weather favorites like broccoli and carrots. The loamy texture provides an incredible head start for any gardener looking to establish deep-rooted perennials.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group B — Moderate Runoff
Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
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 Benton County have?
Benton County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 28% sand, 51% silt, and 20% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Benton County's soil acidic or alkaline?
Benton 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 Benton County?
Benton 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 Benton County's soil?
Based on Benton County's Loam texture, pH of 6.3, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Benton County?
Benton County's dominant soil order is Alfisols. Alfisols are moderate to high base-status soils with a clay-enriched subsoil. They support productive forests and cropland across temperate regions.
Soil & Planting Advisory: Benton County
Soil Verdict
Benton 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
Benton County closely matches the Iowa average hardiness conditions.
Planning your lawn? View lawn care data for Benton 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.