Howard County Soil Data
Howard County, Iowa
USDA SSURGO / PHZMAvg pH
6.2
Texture
Sandy loam
Drainage
Somewhat excessively drained
Organic Matter
4.9%
Hydrologic Group
A
Data Story
About Soil in Howard County, Iowa
Acidic Sandy Loams and Mollisols
Howard County features Mollisols with an average pH of 6.20, which is more acidic than the national median of 6.5. This pH level is also below the Iowa state average of 6.43. The dominant sandy loam texture sets a unique foundation compared to much of the state.
A Gritty, Well-Structured Mix
These soils contain 37.7% sand and 40.0% silt, with only 19.4% clay. This high sand content provides excellent aeration and prevents the soil from becoming overly sticky when wet. It is generally easier to work with early in the spring than heavier clay soils.
High Organic Content in the North
The organic matter level is a robust 4.90%, which is significantly higher than the Iowa average of 3.81%. Although the available water capacity of 0.191 in/in is slightly below the state average, the high organic matter provides a wealth of nutrients. This creates a fertile environment for diverse plant life.
Fast-Draining Soils for Active Gardening
This soil is classified as somewhat excessively drained and belongs to Hydrologic Group A. This means water moves through the profile very quickly, reducing the risk of root rot. However, it also means plants may require more frequent watering during dry spells.
Hardy Growth in Zone 4b
Howard County sits in the cooler Hardiness Zone 4b, requiring plants that can handle harsh winters. The sandy loam soil is perfect for root vegetables like carrots and potatoes that thrive in looser ground. Embrace the fast drainage and high fertility to build a productive cold-climate garden.
Soil Composition
Soil pH
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.
Drainage Class
Somewhat excessively drained
Water is removed rapidly. Soils may be droughty and have limited water-holding capacity.
Soil Profile
Dominant texture: Sandy loam
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Sandy Soil Detected
Sandy soils drain quickly and can dry out. These products boost water retention and organic matter.
Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Howard County have?
Howard County's soil is classified as Sandy loam. This indicates the relative proportions of sand, silt, and clay — 38% sand, 40% silt, and 19% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Howard County's soil acidic or alkaline?
Howard 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 Howard County?
Howard County has a dominant drainage class of "Somewhat excessively drained." Moderate drainage allows adequate moisture retention while still permitting excess water to drain over time.
What crops or plants grow well in Howard County's soil?
Based on Howard County's Sandy loam texture, pH of 6.2, and Somewhat 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 Howard County?
Howard County's dominant soil order is Mollisols. Mollisols are fertile, dark-colored soils that formed under grassland vegetation. They are among the most productive agricultural soils in the world.
Soil & Planting Advisory: Howard County
Soil Verdict
Howard County is in USDA hardiness zone 4b, a cold climate zone. where winter lows can reach -25°F. Soils here experience deep freeze cycles that can disrupt structure, kill shallow roots, and slow microbial activity for months each year.
Planting Guidance
Focus on cold-hardy perennials, native grasses, and conifers. The short growing window favors plants with low heat requirements. With extreme winter lows, any marginally hardy plants need heavy mulch and wind protection. 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
Deep winter freezing can create soil heaving that pushes shallow-rooted plants out of the ground; add 3-4 inches of organic mulch each fall. Soil drainage is critical — frozen, waterlogged soil kills roots faster than cold alone. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Howard County is somewhat cooler than the Iowa statewide average.
Planning your lawn? View lawn care data for Howard 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.