Shelby County Soil Data
Shelby County, Iowa
USDA SSURGO / PHZMAvg pH
6.3
Texture
Silty Clay Loam
Drainage
N/A
Organic Matter
2.9%
Hydrologic Group
N/A
Data Story
About Soil in Shelby County, Iowa
Acidic Profiles in Shelby County
The soil here has an average pH of 6.28, making it notably more acidic than the national median of 6.5. This chemical profile is common in Western Iowa but may require lime applications for certain sensitive crops.
Dominant Silt and Minimal Sand
With a massive 63.6% silt content and only 8.4% sand, this soil feels velvety and holds its shape well. The high silt levels provide a vast surface area for nutrient storage, though the lack of sand can lead to crusting after heavy rains.
Top-Tier Water Holding Potential
Shelby County boasts a water capacity of 0.220 inches per inch, far exceeding the state average of 0.195. While organic matter is below the state average at 2.86%, the superior water retention helps crops survive dry spells.
Water Storage Over Rapid Drainage
The high silt and clay mix suggests a soil that prioritizes storage over drainage, even if formal classes aren't recorded. Gardeners should ensure raised beds are used if they encounter persistent wet spots in low-lying areas.
Lush Gardens in Zone 5b
Zone 5b provides a reliable window for corn and root vegetables that thrive in silty earth. The high water capacity makes this an excellent spot for moisture-loving garden favorites.
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: Silty Clay Loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Clay Soil Detected
Clay soils can struggle with drainage. These products improve soil structure and water flow.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Shelby County have?
Shelby County's soil is classified as Silty Clay Loam. This indicates the relative proportions of sand, silt, and clay — 8% sand, 64% silt, and 28% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Shelby County's soil acidic or alkaline?
Shelby County's soil has a pH of 6.3, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Shelby County?
Drainage class data is not currently available for Shelby County.
What crops or plants grow well in Shelby County's soil?
Based on Shelby County's Silty Clay Loam texture, pH of 6.3, 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 Shelby County?
The dominant USDA soil order for Shelby County is not currently available in our dataset.
Soil & Planting Advisory: Shelby County
Soil Verdict
Shelby County is in USDA hardiness zone 5b, a cold climate zone. where winter lows can reach -15°F. Freeze-thaw cycles are moderate; soil biology slows in winter but recovers reliably in spring, supporting a broad range of plants.
Planting Guidance
A wide plant palette is possible: deciduous trees, most shrubs, cool-season vegetables, and many perennials thrive here. Winter protection (mulch, burlap wraps) helps push the zone boundary for desired species. Always match plant selections to the specific microclimate of your property — low spots, slopes, and wind exposure can shift effective hardiness by half a zone.
Soil Implications
Moderate freeze-thaw cycles naturally aerate the soil but can also cause compaction in clay-heavy areas; annual core aeration is beneficial. Organic matter amendments decompose at a moderate pace — aim for 3-5% organic content for optimal fertility. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Shelby County closely matches the Iowa average hardiness conditions. The zone range of 5a-5b within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Shelby 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.