Benton County Soil Data
Benton County, Oregon
USDA SSURGO / PHZMAvg pH
5.3
Texture
Stratified sand to gravel
Drainage
N/A
Organic Matter
26.3%
Hydrologic Group
N/A
Data Story
About Soil in Benton County, Oregon
The Valley's Rich Acidic Foundation
Benton County features a stratified sand to gravel texture with an average pH of 5.28. This level is nearly identical to the state average of 5.26 but significantly more acidic than the national median of 6.5.
Silt-Heavy Soils for Steady Growth
The soil composition is dominated by 52.4% silt, balanced with 23.6% sand and 22.5% clay. This silty mix offers excellent workability and enough clay to retain essential nutrients for the region's diverse agriculture.
High Organic Content and Water Storage
Benton County boasts a high organic matter content of 26.30%, far exceeding the national 2% average. With an available water capacity of 0.282 in/in, the soil holds slightly more moisture than the Oregon state average.
Managing Stratified Drainage Patterns
The stratified sand and gravel layers suggest varied drainage across the county, though official drainage classes are unassigned. These underground layers typically provide a natural filter for the valley's heavy winter rains.
Success in Zone 8b
With a 73.7 soil score and a mild 8b hardiness zone, this is prime land for berries, nuts, and wine grapes. The soil's natural acidity and high moisture capacity create a perfect environment for iconic Oregon crops.
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: Stratified sand to gravel
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Acidic Soil Detected
Your county's average pH is 5.3. These products help balance soil pH for healthier grass.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Benton County have?
Benton County's soil is classified as Stratified sand to gravel. This indicates the relative proportions of sand, silt, and clay — 24% sand, 52% silt, and 23% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is Benton County's soil acidic or alkaline?
Benton County's soil has a low pH of 5.3, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Benton County?
Drainage class data is not currently available for Benton County.
What crops or plants grow well in Benton County's soil?
Based on Benton County's Stratified sand to gravel texture, pH of 5.3, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, drought-tolerant crops, root vegetables, and sandy-soil specialists.
What USDA soil order is found in Benton County?
The dominant USDA soil order for Benton County is not currently available in our dataset.
Soil & Planting Advisory: Benton County
Soil Verdict
Benton County 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
Benton County is somewhat warmer than the Oregon statewide average.
Planning your lawn? View lawn care data for Benton County on LawnByCounty.com →
Other Counties in Oregon
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.