Adair County Soil Data
Adair County, Missouri
USDA SSURGO / PHZMAvg pH
6.4
Texture
Silty clay loam
Drainage
Well drained
Organic Matter
2.9%
Hydrologic Group
C
Data Story
About Soil in Adair County, Missouri
Neutral Soils in Adair County
Adair County’s soil sits at a pH of 6.43, which is nearly identical to the national median of 6.5. While specific taxonomic data is limited for this region, the soil is significantly less acidic than the Missouri state average of 6.09.
A Balanced Silt-Heavy Mix
The mix of 25.4% sand, 50.3% silt, and 24.2% clay creates a balanced medium for plant roots. This composition offers good workability for farmers while the clay content ensures the soil retains necessary minerals and structure.
Strong Water Storage Potential
With an Available Water Capacity of 0.196 in/in, Adair exceeds the state average of 0.183, helping crops withstand dry spells. Organic matter sits at 2.92%, which is lower than the state’s 4.74% average but remains above the national benchmark of 2.0%.
High Productivity Soil Scores
Specific drainage and hydrologic data are unavailable for this area, though the county's overall soil score of 74.7 suggests a high baseline for productivity. Local growers should monitor moisture levels closely during peak summer months as data is limited.
Zone 6a Gardening Success
Located in USDA Hardiness Zone 6a, this soil is well-suited for staples like sweet corn and tomatoes. With a soil score well above the state average, Adair is an excellent place to start a productive backyard vegetable patch.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group C — Moderate-High Runoff
Soils with slow infiltration rates, often with a layer that impedes downward water movement. Higher clay content restricts drainage.
Drainage Class
Well drained
Water is removed from the soil readily but not rapidly. Optimal for most plants and construction.
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 Adair County have?
Adair County's soil is classified as Silty clay loam. This indicates the relative proportions of sand, silt, and clay — 25% sand, 50% silt, and 24% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Adair County's soil acidic or alkaline?
Adair County's soil has a pH of 6.4, which is moderately acidic. This range suits many crops and is common across much of the eastern US.
What is the drainage class for Adair County?
Adair County has a dominant drainage class of "Well drained." Well-drained soils allow excess water to move through quickly, reducing waterlogging risk and supporting most field and garden crops.
What crops or plants grow well in Adair County's soil?
Based on Adair County's Silty clay loam texture, pH of 6.4, and Well drained, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens, most annual and perennial crops.
What USDA soil order is found in Adair County?
Adair County's dominant soil order is Entisols. Entisols are recently formed soils with little to no horizon development. They are common on floodplains, steep slopes, and sandy deposits.
Soil & Planting Advisory: Adair County
Soil Verdict
Adair County is in USDA hardiness zone 6a, a moderate climate zone. where winter lows can reach -10°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
Adair County closely matches the Missouri average hardiness conditions.
Planning your lawn? View lawn care data for Adair County on LawnByCounty.com →
Other Counties in Missouri
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.