Harrison County Soil Data
Harrison County, Iowa
Avg pH
7.1
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.7%
Hydrologic Group
N/A
Data Story
About Soil in Harrison County, Iowa
Alkaline Soils Dominate the West
Harrison County averages a soil pH of 7.12, making it noticeably more alkaline than the national median of 6.5. This pH level is significantly higher than the Iowa state average of 6.43. Although taxonomic details are not currently specified, this alkaline profile influences which nutrients are most available to plants.
Silt-Dominant Loess-Like Soils
The soil contains a heavy 59.2% silt and 25.2% clay, with only 15.6% sand. This composition is typical of the Loess Hills region, offering a fine-textured soil that holds onto moisture exceptionally well. It is highly productive but can be prone to erosion if left uncovered.
High Water Storage Despite Lower Organic Matter
Organic matter sits at 2.66%, which is below the Iowa average of 3.81% but still above the national average of 2.0%. Despite lower organic levels, the available water capacity is high at 0.200 in/in. This allows the soil to act as a deep reservoir for crops during dry spells.
Hydrology in the Loess Hills
Specific drainage and hydrologic group classifications are not provided in the current dataset. However, the silt-heavy nature of these soils often means they drain slowly and require careful management to prevent runoff. The overall soil score of 63.7 reflects these unique regional challenges.
Thriving in Zone 5b Soils
Hardiness Zone 5b allows for a slightly longer growing season, making these silty soils great for deep-rooted perennials and grains. Because the pH is over 7.0, you might choose plants that tolerate alkaline conditions, like asparagus or lavender. Adding compost can help improve the organic matter and boost your garden's health.
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 Harrison County have?
Harrison County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 16% sand, 59% silt, and 25% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Harrison County's soil acidic or alkaline?
Harrison County's soil has a pH of 7.1, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Harrison County?
Drainage class data is not currently available for Harrison County.
What crops or plants grow well in Harrison County's soil?
Based on Harrison County's Silt Loam texture, pH of 7.1, and drainage class, the soil is well suited for drought-tolerant crops and native grasses, row crops and vegetable gardens.
What USDA soil order is found in Harrison County?
The dominant USDA soil order for Harrison County is not currently available in our dataset.
Planning your lawn? View lawn care data for Harrison County on LawnByCounty.com →
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.