Sangamon County Soil Data
Sangamon County, Illinois
USDA SSURGO / PHZMAvg pH
6.5
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.6%
Hydrologic Group
N/A
Data Story
About Soil in Sangamon County, Illinois
High-Quality Soils in the State Capital
Sangamon County features a highly productive soil profile with an average pH of 6.54, slightly above the national median of 6.5. This near-neutrality is more favorable for agriculture than the 6.39 state average. While specific taxonomic orders are not documented, the chemical balance supports the county's impressive 79.6 soil score.
Dense Silt for Superior Nutrient Retention
The soil composition is dominated by 68.1% silt, one of the highest concentrations in the region. With only 8.5% sand and 23.4% clay, the soil is exceptionally fine-textured and rich. This mix provides an incredible surface area for holding plant nutrients, making it world-class farmland.
Top-Tier Water Capacity and Organic Richness
The organic matter content is 2.64%, well above the national average of 2.0%. Most impressively, the available water capacity of 0.213 in/in exceeds the state average of 0.204. This high capacity ensures that crops have deep reservoirs of moisture to pull from throughout the growing season.
Fine Textures Demand Careful Drainage
With a very low sand percentage of 8.5%, natural drainage can be slow as water moves primarily through silty pores. Although specific hydrologic groups are unlisted, these soils are known for their ability to hold water rather than shedding it quickly. This makes them drought-resistant but potentially slow to dry in the spring.
A Gardener's Dream in Zone 6a
Located in Zone 6a, Sangamon County is perfect for high-yield vegetables like tomatoes, peppers, and corn. The high soil score of 79.6 suggests that almost anything you plant will find the nutrients it needs. Start your backyard plot today to take advantage of some of the best dirt in Illinois.
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 Sangamon County have?
Sangamon County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 9% sand, 68% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Sangamon County's soil acidic or alkaline?
Sangamon County's soil has a pH of 6.5, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Sangamon County?
Drainage class data is not currently available for Sangamon County.
What crops or plants grow well in Sangamon County's soil?
Based on Sangamon County's Silt Loam texture, pH of 6.5, 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 Sangamon County?
The dominant USDA soil order for Sangamon County is not currently available in our dataset.
Soil & Planting Advisory: Sangamon County
Soil Verdict
Sangamon County is in USDA hardiness zone 6a, a moderate climate zone. where winter lows can reach -10°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
Sangamon County closely matches the Illinois average hardiness conditions.
Planning your lawn? View lawn care data for Sangamon 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.