Macoupin County Soil Data
Macoupin County, Illinois
USDA SSURGO / PHZMAvg pH
6.3
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.2%
Hydrologic Group
N/A
Data Story
About Soil in Macoupin County, Illinois
Acidic Silty Loams
Macoupin County has an average pH of 6.34, making it more acidic than the national median and the Illinois state average. Despite this acidity, the county maintains a respectable soil score of 73.2.
Silt-Heavy Soil Profile
The soil is dominated by silt at 67.1%, one of the highest percentages in the state, with only 11% sand. This makes for a very smooth soil that holds water exceptionally well but can be easily compacted by heavy machinery.
Deep Water Reserves
Available water capacity is high at 0.211 in/in, surpassing the state average of 0.204 in/in. Although organic matter is slightly lower at 2.24%, the soil’s ability to store water makes it quite resilient.
Moisture-Rich Landscapes
Specific drainage classes are not listed, but the high silt content and high water capacity suggest a soil that stays damp. This is excellent for moisture-loving plants but may require soil amendments to improve aeration for some species.
Southern Growth in Zone 6b
Located in Hardiness Zone 6b, Macoupin County benefits from a mild climate and a long growing season. The deep water reserves in the soil are perfect for maintaining a productive garden even during the peak of summer.
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 Macoupin County have?
Macoupin County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 11% sand, 67% silt, and 22% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Macoupin County's soil acidic or alkaline?
Macoupin 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 Macoupin County?
Drainage class data is not currently available for Macoupin County.
What crops or plants grow well in Macoupin County's soil?
Based on Macoupin 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 Macoupin County?
The dominant USDA soil order for Macoupin County is not currently available in our dataset.
Soil & Planting Advisory: Macoupin County
Soil Verdict
Macoupin County is in USDA hardiness zone 6b, a moderate climate zone. where winter lows can reach -5°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
Macoupin County closely matches the Illinois average hardiness conditions. The zone range of 6a-6b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Macoupin 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.