Mercer County Soil Data
Mercer County, Illinois
USDA SSURGO / PHZMAvg pH
6.4
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.3%
Hydrologic Group
N/A
Data Story
About Soil in Mercer County, Illinois
Standard Midwestern Acidity in Mercer
Mercer County maintains an average soil pH of 6.42, placing it very close to the national median of 6.5 and slightly above the Illinois average. This slightly acidic profile is ideal for the nutrient uptake required by most regional field crops.
Fine-Grained Soil with High Silt
A heavy silt concentration of 63.8% defines the local texture, supported by 22.1% clay and 14.1% sand. This composition creates a fertile, fine-grained earth that is easy to till but requires careful management to prevent surface compaction.
Consistent Hydration for Thirsty Roots
Organic matter levels reach 2.30%, which exceeds the national average of 2.0% even if it trails the state's 2.94% mark. The available water capacity of 0.205 in/in ensures that crops have steady access to hydration throughout the growing season.
Observe Water Movement on Site
Detailed drainage class and hydrologic group data are not currently available for this county’s overall profile. Growers should observe how water moves across their land after heavy rains to assess the specific drainage needs of their planting site.
Ready for Cool-Season Success
Mercer County falls within USDA Hardiness Zone 5b, favoring cool-season vegetables and hardy perennials. The high silt content and reliable water capacity provide an excellent environment for establishing a productive home vegetable patch.
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.
USDA Soil Orders
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Mercer County have?
Mercer County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 14% sand, 64% silt, and 22% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Mercer County's soil acidic or alkaline?
Mercer 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 Mercer County?
Drainage class data is not currently available for Mercer County.
What crops or plants grow well in Mercer County's soil?
Based on Mercer County's Silt 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 Mercer County?
The dominant USDA soil order for Mercer County is not currently available in our dataset.
Soil & Planting Advisory: Mercer County
Soil Verdict
Mercer 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
Mercer County is somewhat cooler than the Illinois statewide average.
Planning your lawn? View lawn care data for Mercer 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.