Marion County Soil Data
Marion County, Kentucky
USDA SSURGO / PHZMAvg pH
5.7
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.0%
Hydrologic Group
N/A
Data Story
About Soil in Marion County, Kentucky
Marion's Acidic Silt-Rich Earth
Marion County scores a 53.1 for soil quality, placing it slightly below the state average of 56.2. The average pH of 5.74 is more acidic than both the state average and the national median of 6.5.
Dominant Silt and Clay Profiles
The soil is comprised of 60.1% silt and 23.5% clay, giving it a smooth texture that holds water well. A relatively low sand content of 16.4% means the soil can become compact if worked when too wet.
High Water Capacity and Moderate Matter
Organic matter sits at 2.00%, matching the national average but trailing the Kentucky average of 3.55%. However, the available water capacity of 0.192 in/in is higher than the state norm, helping plants survive dry spells.
Hydraulic Management in Marion
Data for dominant drainage classes and taxonomic orders is not currently available for this area. Given the high silt levels, gardeners should be mindful of surface crusting and ensure adequate aeration for healthy roots.
Extended Growing in Zone 7a
With a Hardiness Zone of 7a, Marion County is well-suited for long-season crops like melons and squash. Boosting your soil with organic compost will help unlock the true potential of your local land.
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
Acidic Soil Detected
Your county's average pH is 5.7. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Marion County have?
Marion County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 16% sand, 60% silt, and 24% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Marion County's soil acidic or alkaline?
Marion County's soil has a pH of 5.7, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Marion County?
Drainage class data is not currently available for Marion County.
What crops or plants grow well in Marion County's soil?
Based on Marion County's Silt Loam texture, pH of 5.7, 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 Marion County?
The dominant USDA soil order for Marion County is not currently available in our dataset.
Soil & Planting Advisory: Marion County
Soil Verdict
Marion County is in USDA hardiness zone 7a, a moderate climate zone. where winter lows can reach 0°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.
Planting Guidance
Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. 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
Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Marion County closely matches the Kentucky average hardiness conditions.
Planning your lawn? View lawn care data for Marion County on LawnByCounty.com →
Other Counties in Kentucky
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.