Columbia County Soil Data
Columbia County, Oregon
Avg pH
5.2
Texture
Silt Loam
Drainage
N/A
Organic Matter
29.5%
Hydrologic Group
N/A
Data Story
About Soil in Columbia County, Oregon
Classic Oregon Lowland Soils
Columbia County soil has an average pH of 5.18, aligning closely with the state average of 5.26. Like most of the Pacific Northwest, these soils are more acidic than the national median of 6.5, requiring lime for many garden crops.
A Heavy Silt Profile
Silt makes up 53.6% of the soil composition, supported by 28.5% sand and 16.9% clay. This silty texture is common in river-adjacent counties, providing a smooth, workable medium that holds moisture without excessive compaction.
Strong Organic Benchmarks
With 29.50% organic matter, Columbia County sits right at the state average and vastly exceeds the national average of 2%. The available water capacity of 0.281 in/in ensures that crops have steady access to moisture during the peak summer.
Functional River-Region Hydrology
While official drainage classes aren't listed, the high silt and sand content suggests moderate permeability. This balance is critical for maintaining soil health in a region characterized by significant annual precipitation.
Abundant Growth in Zone 8b
Columbia County's 8b hardiness zone and 71.8 soil score support a thriving timber and agriculture sector. It is an excellent place for cool-season vegetables like brassicas and leafy greens which thrive in the county's damp, organic-rich soil.
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
Frequently Asked Questions
What type of soil does Columbia County have?
Columbia County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 28% sand, 54% silt, and 17% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Columbia County's soil acidic or alkaline?
Columbia County's soil has a low pH of 5.2, which is strongly acidic. Acidic soils benefit from lime applications to raise pH and improve nutrient availability.
What is the drainage class for Columbia County?
Drainage class data is not currently available for Columbia County.
What crops or plants grow well in Columbia County's soil?
Based on Columbia County's Silt Loam texture, pH of 5.2, and drainage class, the soil is well suited for acid-loving plants like blueberries and azaleas, row crops and vegetable gardens.
What USDA soil order is found in Columbia County?
The dominant USDA soil order for Columbia County is not currently available in our dataset.
Planning your lawn? View lawn care data for Columbia 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.