Decatur County Soil Data
Decatur County, Iowa
Avg pH
6.2
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.7%
Hydrologic Group
N/A
Data Story
About Soil in Decatur County, Iowa
Slightly Acidic Soils of the South
Decatur County soils have an average pH of 6.18, which is more acidic than the state average of 6.43. This acidity level can influence how plants absorb minerals, often requiring amendments for peak productivity. The soil score of 66.5 reflects a challenging but manageable landscape compared to the state's 72.9 average.
Fine Texture with Moderate Clay
The soil mix is 51.1% silt, 26.9% clay, and 21.9% sand, creating a dense and fine-textured earth. The higher clay content compared to neighboring counties improves nutrient retention but can make the soil heavy to till when wet. This composition is typical for the rolling hills of southern Iowa.
Steady Moisture in Moderate Soils
Organic matter sits at 2.70%, beating the national average of 2.0% but falling short of the state’s 3.81% benchmark. The available water capacity of 0.194 in/in is almost identical to the state average of 0.195. This indicates that while the soil isn't the richest in the state, it handles moisture reliably.
Reliable Hydrology for Diverse Land Use
Decatur's soil water capacity suggests a stable hydrologic environment for both farming and building. Because the clay content is nearly 27%, the soil may hold water longer than sandier northern counties. This necessitates good drainage planning for any new construction or intensive garden beds.
Vibrant Growth in Zone 5b
Decatur County resides in Zone 5b, where the soil and climate support robust hay, pasture, and row crops. Gardeners should focus on adding compost to improve the 2.70% organic matter for better yields. With the right care, this soil produces excellent root vegetables and hardy perennials.
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 Decatur County have?
Decatur County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 22% sand, 51% silt, and 27% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Decatur County's soil acidic or alkaline?
Decatur County's soil has a pH of 6.2, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Decatur County?
Drainage class data is not currently available for Decatur County.
What crops or plants grow well in Decatur County's soil?
Based on Decatur County's Silt Loam texture, pH of 6.2, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Decatur County?
The dominant USDA soil order for Decatur County is not currently available in our dataset.
Planning your lawn? View lawn care data for Decatur 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.