Sullivan County Soil Data
Sullivan County, Indiana
USDA SSURGO / PHZMAvg pH
6.2
Texture
Fine sandy loam
Drainage
Well drained
Organic Matter
3.0%
Hydrologic Group
B
Data Story
About Soil in Sullivan County, Indiana
Sullivan's Balanced and Productive Alfisols
Sullivan County sits on Alfisols, a taxonomic order known for being naturally productive and stable. The average pH of 6.24 is higher than the state average of 6.08 and approaches the national median of 6.5. This balanced pH level is ideal for most Midwestern crops and garden plants.
Fine Sandy Loam for Easy Tilling
The dominant texture is fine sandy loam, composed of 53.4% silt and 29% sand. With 16.4% clay, the soil maintains enough structure to hold nutrients without becoming difficult to till. This balance makes it one of the most workable soil types in the region.
Consistent Moisture for Healthy Crops
Organic matter is 3.02%, which exceeds the national average but falls below the state average of 4.90%. The available water capacity of 0.194 in/in provides a consistent supply of moisture to plant roots. This ensures that crops can withstand brief dry spells during the peak of summer.
Superior Drainage for Farming and Building
The soil is classified as well drained and belongs to hydrologic group B. This means water moves through the profile at an ideal rate, preventing standing water while keeping the soil moist. These conditions are excellent for residential construction and diverse agricultural uses.
The Perfect Gardening Spot in Zone 6b
Sullivan County's zone 6b climate supports everything from corn and soy to delicate perennials and fruit trees. The well-drained loamy soil is a significant asset for any home gardener. Now is the time to plant a vegetable patch or an orchard in this versatile ground.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group B — Moderate Runoff
Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Fine sandy loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Sandy Soil Detected
Sandy soils drain quickly and can dry out. These products boost water retention and organic matter.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Sullivan County have?
Sullivan County's soil is classified as Fine sandy loam. This indicates the relative proportions of sand, silt, and clay — 29% sand, 53% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Sullivan County's soil acidic or alkaline?
Sullivan County's soil has a pH of 6.2, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Sullivan County?
Sullivan County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in Sullivan County's soil?
Based on Sullivan County's Fine sandy loam texture, pH of 6.2, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Sullivan County?
Sullivan County's dominant soil order is Alfisols. Alfisols are moderate to high base-status soils with a clay-enriched subsoil. They support productive forests and cropland across temperate regions.
Soil & Planting Advisory: Sullivan County
Soil Verdict
Sullivan 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
Sullivan County closely matches the Indiana 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 Sullivan County on LawnByCounty.com →
Other Counties in Indiana
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.