Hamilton County Soil Data
Hamilton County, Iowa
USDA SSURGO / PHZMAvg pH
6.6
Texture
Loam
Drainage
N/A
Organic Matter
6.8%
Hydrologic Group
N/A
Data Story
About Soil in Hamilton County, Iowa
Hamilton's Elite Agricultural Score
Hamilton County boasts a staggering soil score of 85.4, one of the highest in the region. Its pH of 6.57 is nearly perfect for nutrient availability, sitting just above the 6.5 national median.
Balanced Mix of Sand and Clay
The soil contains 35.3% sand and 38.4% silt, providing a versatile and porous growing medium. With 24.5% clay, the soil has the perfect amount of body to hold its shape and retain nutrients.
Extraordinary Organic Riches
At 6.79%, the organic matter content is more than triple the national average and far above the state average. This is paired with a high water capacity of 0.201 in/in, making this some of the most fertile land in Iowa.
Natural Strength and Water Management
While specific drainage classes are not recorded, the high soil score suggests superior natural performance. The exceptional organic load acts as a sponge, managing moisture levels effectively for any crop.
Unmatched Growing Potential in Zone 5a
The Zone 5a climate and elite soil quality allow for legendary harvests of corn, soybeans, and vegetables. Whether you are a farmer or a hobbyist, this soil is a dream to plant in.
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
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Hamilton County have?
Hamilton County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 35% sand, 38% silt, and 25% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Hamilton County's soil acidic or alkaline?
Hamilton County's soil has a pH of 6.6, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Hamilton County?
Drainage class data is not currently available for Hamilton County.
What crops or plants grow well in Hamilton County's soil?
Based on Hamilton County's Loam texture, pH of 6.6, 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 Hamilton County?
The dominant USDA soil order for Hamilton County is not currently available in our dataset.
Soil & Planting Advisory: Hamilton County
Soil Verdict
Hamilton 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
Hamilton County closely matches the Iowa average hardiness conditions.
Planning your lawn? View lawn care data for Hamilton 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.