Dubuque County Soil Data

Dubuque County, Iowa

Avg pH

6.4

Texture

Loamy fine sand

Drainage

Excessively drained

Organic Matter

2.5%

Hydrologic Group

A

Data Story

About Soil in Dubuque County, Iowa

Entisols of the Driftless Area

Dubuque County is home to Entisols, which are young soils often found on steep or shifting landscapes. The average pH of 6.38 is very close to the Iowa state average of 6.43, providing a familiar chemical environment for local farmers. Its soil score of 71.4 sits just slightly below the state average of 72.9.

Loamy Fine Sand and High Silt

The dominant texture is loamy fine sand, though the overall county average is 52.5% silt and 27.5% sand. This mixture creates a unique physical profile that is easy to till but requires careful management to prevent erosion. The 19.3% clay content is relatively low, making the soil feel lighter and more porous.

Superior Water Capacity for Growing

Despite a lower organic matter content of 2.55%, Dubuque County features an impressive available water capacity of 0.197 in/in. This exceeds the state average of 0.195, meaning the soil is excellent at storing water for plant use. This trait is vital for maintaining productivity in the county's diverse topography.

Excessively Drained for Fast Drying

Classified as 'excessively drained' and part of Hydrologic Group A, this soil sheds water very quickly. While this prevents root rot, it also means plants may need more frequent watering during dry spells. These drainage characteristics are typical for the rugged, unglaciated terrain found in this part of the state.

Elevated Gardening in Zone 5a

In Zone 5a, Dubuque's fast-draining soils are ideal for plants that hate 'wet feet,' such as lavender or Mediterranean herbs. The high water capacity ensures that once you water, the soil holds that moisture deep where roots need it. Use the natural slopes of the county to create a stunning, well-drained terraced garden.

Soil Composition

Loamy fine sand
Sand: 27.5%
Silt: 52.5%
Clay: 19.3%
Loamy fine sand

Soil pH

6.4pH
6.38054892153221
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 A — Low Runoff

Sandy, well-drained soils with high infiltration rates. Water moves quickly through the soil profile. Lowest runoff potential when thoroughly wetted.

Runoff potential:Low

Drainage Class

Excessively drained

Water is removed very rapidly. Very sandy or gravelly soils with little water retention.

Soil Profile

Dominant texture: Loamy fine sand

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 Dubuque County have?

Dubuque County's soil is classified as Loamy fine sand. This indicates the relative proportions of sand, silt, and clay — 27% sand, 52% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.

Is Dubuque County's soil acidic or alkaline?

Dubuque County's soil has a pH of 6.4, which is moderately acidic. This range suits many crops and is common across much of the eastern US.

What is the drainage class for Dubuque County?

Dubuque County has a dominant drainage class of "Excessively drained." Moderate drainage allows adequate moisture retention while still permitting excess water to drain over time.

What crops or plants grow well in Dubuque County's soil?

Based on Dubuque County's Loamy fine sand texture, pH of 6.4, and Excessively drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.

What USDA soil order is found in Dubuque County?

Dubuque County's dominant soil order is Entisols. Entisols are recently formed soils with little to no horizon development. They are common on floodplains, steep slopes, and sandy deposits.

Other Counties in Iowa

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.