Tillman County Soil Data
Tillman County, Oklahoma
USDA SSURGO / PHZMAvg pH
7.0
Texture
Water
Drainage
N/A
Organic Matter
1.3%
Hydrologic Group
D
Data Story
About Soil in Tillman County, Oklahoma
Neutral to Alkaline Soils in Tillman
Tillman County features a soil pH of 6.96, which is nearly neutral and higher than the national median of 6.5. This puts the county well above the Oklahoma state average pH of 6.06. Such a profile is excellent for nutrient availability in many agricultural applications.
A Balanced and Clay-Rich Mix
With 36.8% sand, 33.1% silt, and 21.4% clay, the soil has a robust, well-distributed texture. The 21.4% clay content is higher than many neighboring counties, providing superior nutrient retention and soil structure. This mix supports the county's soil score of 31.1.
Resilient Texture vs Lower Organic Matter
Organic matter is 1.28%, falling below the state average of 1.72%. The available water capacity of 0.134 in/in is also slightly lower than the state average of 0.144 in/in. Despite these numbers, the balanced clay content helps manage the moisture that is available.
Managing Water in Hydrologic Group D
Tillman County belongs to Hydrologic Group D, which is prone to high runoff and slow infiltration. The clay-rich composition can lead to heavy, sticky soils when wet and hard-packed conditions when dry. Careful timing of tilling and planting is required to maintain soil health.
Zone 8a: A Long Season for Heat Lovers
The warm Zone 8a climate allows for an exceptionally long growing season for crops like peppers, tomatoes, and melons. The near-neutral pH means most plants can easily access soil minerals without much adjustment. Adding compost will help improve the water capacity and organic matter for peak production.
Soil Composition
Soil pH
Soil Series
Detailed soil series data not yet available for this county.
Hydrologic Group
Group D — High Runoff
Clay soils with very slow infiltration rates. Highest runoff potential. These soils have a permanent high water table or are shallow over impervious material.
Drainage Class
Drainage class data not available.
Soil Profile
Dominant texture: Water
Typical soil profile. Actual depths vary by location.
USDA Soil Orders
Soil Amendment Products
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Browse Soil AmendmentsFrequently Asked Questions
What type of soil does Tillman County have?
Tillman County's soil is classified as Water. This indicates the relative proportions of sand, silt, and clay — 37% sand, 33% silt, and 21% clay. Sandy soils drain quickly but may need more frequent irrigation and fertilization.
Is Tillman County's soil acidic or alkaline?
Tillman County's soil has a pH of 7.0, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Tillman County?
Drainage class data is not currently available for Tillman County.
What crops or plants grow well in Tillman County's soil?
Based on Tillman County's Water texture, pH of 7.0, and drainage class, the soil is well suited for vegetables, grains, and most field crops.
What USDA soil order is found in Tillman County?
The dominant USDA soil order for Tillman County is not currently available in our dataset.
Soil & Planting Advisory: Tillman County
Soil Verdict
Tillman County is in USDA hardiness zone 8a, a warm climate zone. where winter lows can reach 10°F. Mild winters mean soil rarely freezes deeply, allowing year-round microbial activity and faster organic matter breakdown.
Planting Guidance
Warm-season crops, citrus relatives, and heat-loving ornamentals do well. Cool-season vegetables should be planted in fall and winter. 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
Warm soils accelerate organic matter breakdown, so compost and mulch need replenishing more frequently than in cooler zones. Sandy soils common in warm zones drain quickly; water-retentive amendments like compost or peat help hold moisture.
Regional Context
Tillman County is somewhat warmer than the Oklahoma statewide average. The zone range of 7b-8a within the county means soil and planting decisions should account for local elevation and topography.
Planning your lawn? View lawn care data for Tillman County on LawnByCounty.com →
Other Counties in Oklahoma
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.