Clay County Soil Data
Clay County, South Dakota
USDA SSURGO / PHZMAvg pH
7.2
Texture
Clay Loam
Drainage
N/A
Organic Matter
3.2%
Hydrologic Group
N/A
Data Story
About Soil in Clay County, South Dakota
The alkaline profile of Clay County
Clay County’s soil pH averages 7.18, which is slightly more alkaline than the state average of 7.05. This profile requires monitoring for iron availability, as higher pH can occasionally lock out specific micronutrients.
A heavy, silty texture profile
Silt dominates the landscape at 47.0%, while clay accounts for 27.6% of the composition. This results in a soil that is heavier and more nutrient-dense than sandier neighboring regions.
Consistent available water capacity
The soil contains 3.16% organic matter and an available water capacity of 0.177 in/in. While slightly below the state average of 0.182, these numbers still represent a highly productive environment for Missouri Valley farming.
Steady water movement for farms
Specific drainage classes are not listed, but the soil score of 56.2 indicates respectable land quality. The high silt and clay content suggests that water moves through the profile at a moderate, steady pace.
Warmer growing in zone 5a
Zone 5a status offers a longer growing season than much of South Dakota. This soil is excellent for tomatoes and peppers, which appreciate the nutrient retention provided by the clay and silt.
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: 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 Clay County have?
Clay County's soil is classified as Clay Loam. This indicates the relative proportions of sand, silt, and clay — 25% sand, 47% silt, and 28% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Clay County's soil acidic or alkaline?
Clay County's soil has a pH of 7.2, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Clay County?
Drainage class data is not currently available for Clay County.
What crops or plants grow well in Clay County's soil?
Based on Clay County's Clay Loam texture, pH of 7.2, 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 Clay County?
The dominant USDA soil order for Clay County is not currently available in our dataset.
Soil & Planting Advisory: Clay County
Soil Verdict
Clay County is in USDA hardiness zone 5a, a cold climate zone. where winter lows can reach -20°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. 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
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
Clay County is somewhat warmer than the South Dakota statewide average.
Planning your lawn? View lawn care data for Clay County on LawnByCounty.com →
Other Counties in South Dakota
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.