Union Parish Soil Data
Union Parish, Louisiana
USDA SSURGO / PHZMAvg pH
5.1
Texture
Silt loam
Drainage
Poorly drained
Organic Matter
1.7%
Hydrologic Group
D
Data Story
About Soil in Union Parish, Louisiana
The Weathered Alfisols of Union
Union Parish soils are acidic with a pH of 5.15, falling below the state average of 5.74. These are classified as Alfisols, which are older, more weathered soils typical of North Louisiana's uplands.
Silt Loam with High Sand Content
The soil is a silt loam with 49.8% sand, 34.6% silt, and 15.6% clay. This high sand percentage makes it easier to till than the heavy clays found in the southern parishes.
Challenges in Organic Retention
Organic matter is low at 1.68%, trailing both state and national averages. The available water capacity of 0.151 in/in is also below the state benchmark, meaning these soils can dry out quickly.
Poorly Drained Group D Soils
Despite the sand content, these soils are classified as poorly drained and belong to hydrologic group D. This indicates a high runoff potential and a layer that restricts water from moving downward easily.
Acid-Loving Plants for Zone 8b
Zone 8b is perfect for camellias and gardenias that love the natural acidity here. Although the soil score is 24.4, your garden will thrive if you supplement it with organic mulch and consistent watering.
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
Poorly drained
Water is removed so slowly that the soil is wet at or near the surface much of the year. Drainage improvement usually needed.
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 5.1. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Union Parish have?
Union Parish's soil is classified as Silt loam. This indicates the relative proportions of sand, silt, and clay — 50% sand, 35% silt, and 16% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Union Parish's soil acidic or alkaline?
Union Parish's soil has a low pH of 5.1, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Union Parish?
Union Parish has a dominant drainage class of "Poorly drained." Poorly drained soils retain water for extended periods, which can limit crop choices and may require tile drainage or raised beds.
What crops or plants grow well in Union Parish's soil?
Based on Union Parish's Silt loam texture, pH of 5.1, and Poorly drained, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens, rice, cranberries, and other water-tolerant species.
What USDA soil order is found in Union Parish?
Union Parish'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: Union Parish
Soil Verdict
Union Parish is in USDA hardiness zone 8b, a warm climate zone. where winter lows can reach 15°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. 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.
Regional Context
Union Parish is somewhat cooler than the Louisiana statewide average.
Planning your lawn? View lawn care data for Union Parish on LawnByCounty.com →
Other Counties in Louisiana
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.