Iroquois County Soil Data
Iroquois County, Illinois
USDA SSURGO / PHZMAvg pH
6.4
Texture
Loam
Drainage
N/A
Organic Matter
5.1%
Hydrologic Group
N/A
Data Story
About Soil in Iroquois County, Illinois
Iroquois County's Balanced Chemistry
Iroquois County features an average soil pH of 6.38, which is nearly identical to the state average of 6.39. This provides a stable chemical environment that doesn't usually require heavy adjustment for standard crops. It represents a solid middle ground between national and regional benchmarks.
Coarser Texture, Better Workability
This county has a higher sand content than most at 26.7%, mixed with 46.5% silt and 24.1% clay. This coarser texture makes the soil easier to till and less prone to the heavy compaction seen in silt-only soils. It provides a unique physical profile that balances drainage with structural stability.
Massive Organic Nutrient Wealth
Iroquois County boasts a remarkable 5.09% organic matter, which is among the highest in the state and far exceeds the 2.94% Illinois average. However, the available water capacity is lower than average at 0.179 in/in. While the soil is incredibly fertile, it may require more frequent watering during extreme droughts.
Managing High-Performance Land
The soil score of 72.8 is very close to the state average of 73.6, indicating reliable agricultural performance. The higher sand content helps with vertical water movement, although the lower water capacity suggests the soil doesn't hold moisture as long as others. This makes it an excellent choice for crops that prefer well-aerated roots.
Rich Harvests in Zone 5b
The 5b hardiness zone is classic Illinois, supporting staples like soybeans and root vegetables. With over 5% organic matter, this soil is a powerhouse for organic gardening and high-yield produce. Your plants will find plenty of natural fuel here to grow large and healthy.
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 Iroquois County have?
Iroquois County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 27% sand, 47% silt, and 24% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Iroquois County's soil acidic or alkaline?
Iroquois 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 Iroquois County?
Drainage class data is not currently available for Iroquois County.
What crops or plants grow well in Iroquois County's soil?
Based on Iroquois County's Loam texture, pH of 6.4, 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 Iroquois County?
The dominant USDA soil order for Iroquois County is not currently available in our dataset.
Soil & Planting Advisory: Iroquois County
Soil Verdict
Iroquois 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
Iroquois County is somewhat cooler than the Illinois statewide average. The zone range of 5b-6a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Iroquois County on LawnByCounty.com →
Other Counties in Illinois
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.