Adams County Soil Data

Adams County, Washington

Avg pH

7.3

Texture

Cobbly loam

Drainage

Well drained

Organic Matter

1.3%

Hydrologic Group

B

Data Story

About Soil in Adams County, Washington

Alkaline Aridisols of the High Desert

Adams County features alkaline Aridisols with a pH of 7.35, which is significantly higher than the national median of 6.5. This cobbly loam texture reflects the dry, rugged environment characteristic of eastern Washington.

A Gritty and Silt-Heavy Mix

The soil consists of 40.4% sand and 48.1% silt, creating a balanced but somewhat gritty profile. With only 8.6% clay, these soils are easy to work but may struggle to hold onto nutrients compared to heavier clay-based soils.

Managing Moisture in Dry Ground

Organic matter sits at 1.35%, falling below the state average of 14.85% and the national average of 2.0%. The available water capacity of 0.166 in/in indicates a need for careful irrigation to maximize growing potential in this thirsty soil.

Well-Drained Ground for Stable Use

These soils are well drained and belong to hydrologic group B, which helps prevent pooling during heavy rains. This efficient drainage makes the land suitable for both dryland farming and stable construction projects.

Hardy Crops for Zone 7a

In hardiness zone 7a, this soil supports robust wheat production and drought-tolerant perennials. Start your garden with native species or install drip irrigation to help your vegetables thrive in this arid climate.

Soil Composition

Cobbly loam
Sand: 40.4%
Silt: 48.1%
Clay: 8.6%
Cobbly loam

Soil pH

7.3pH
7.34902434462502
Strongly AcidicSlightly AcidicNeutralSlightly AlkalineStrongly Alkaline
Ideal lawn range: 6.0 - 7.0

Soil Series

Detailed soil series data not yet available for this county.

Hydrologic Group

Group B — Moderate Runoff

Moderately deep, moderately well-drained soils with moderate infiltration rates. Good balance of drainage and water retention.

Runoff potential:Moderate

Drainage Class

Well drained

Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.

Soil Profile

Dominant texture: Cobbly loam

O HorizonOrganic layer
0-2"
A HorizonTopsoil
2-10"
B HorizonSubsoil
10-30"
C HorizonParent material
30-60"
R HorizonBedrock
60"+

Typical soil profile. Actual depths vary by location.

Frequently Asked Questions

What type of soil does Adams County have?

Adams County's soil is classified as Cobbly loam. This indicates the relative proportions of sand, silt, and clay — 40% sand, 48% silt, and 9% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Adams County's soil acidic or alkaline?

Adams County's soil has a pH of 7.3, which is near neutral. This range is ideal for most garden plants and field crops.

What is the drainage class for Adams County?

Adams 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 Adams County's soil?

Based on Adams County's Cobbly loam texture, pH of 7.3, and Well drained, the soil is well suited for drought-tolerant crops and native grasses, row crops and vegetable gardens, most annual and perennial crops.

What USDA soil order is found in Adams County?

Adams County's dominant soil order is Aridisols. Aridisols are soils of dry environments with low organic matter. They often have salt or calcium carbonate accumulations at depth.

Other Counties in Washington

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.