Union County Soil Data
Union County, South Carolina
Avg pH
5.7
Texture
Sandy loam
Drainage
Well drained
Organic Matter
1.1%
Hydrologic Group
D
Data Story
About Soil in Union County, South Carolina
Alfisols provide a balanced foundation
Union County features Alfisols and sandy loam with a pH of 5.71. This is the most alkaline soil in this group, sitting well above the state average of 5.27 though still more acidic than the national median of 6.5.
Classic sandy loam profile
The soil is composed of 66.4% sand, 18.2% silt, and 15.5% clay. This sandy loam texture offers a great balance of aeration and enough clay to help retain essential nutrients for plant growth.
Moderate moisture and organic levels
Organic matter stands at 1.12%, while the available water capacity is a solid 0.123 in/in. These figures indicate reliable soil that outperforms the state average for water retention, despite having lower organic content than the 2.05% state benchmark.
Rapid drainage with high runoff potential
While the soil is well-drained, its classification in hydrologic group D suggests a high potential for runoff during heavy storms. This requires careful management to prevent erosion on sloped farmland and gardens.
Cultivating success in hardiness zone 8a
Union’s soil and climate are particularly well-suited for timber production and grains like corn or wheat. The relatively high pH makes it a great place to start a vegetable garden with less need for intensive liming.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group D — High Runoff
Clay soils with very slow infiltration rates. Highest runoff potential. These soils have a permanent high water table or are shallow over impervious material.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
Soil Profile
Dominant texture: Sandy loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Frequently Asked Questions
What type of soil does Union County have?
Union County's soil is classified as Sandy loam. This indicates the relative proportions of sand, silt, and clay — 66% sand, 18% silt, and 15% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Union County's soil acidic or alkaline?
Union 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 Union County?
Union 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 Union County's soil?
Based on Union County's Sandy loam texture, pH of 5.7, 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 Union County?
Union 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.
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Other Counties in South Carolina
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.