Tama County Soil Data
Tama County, Iowa
USDA SSURGO / PHZMAvg pH
6.3
Texture
Loam
Drainage
Moderately well drained
Organic Matter
2.5%
Hydrologic Group
D
Data Story
About Soil in Tama County, Iowa
Young Entisols of Tama County
The soil here is primarily classified as Entisols, which are geologically young and lack distinct horizons. With a pH of 6.30, it is slightly more acidic than the state average of 6.43.
Silty Loam with High Retention
The mix of 58.9% silt and 23.1% clay creates a loamy texture that is excellent for holding onto nutrients. Only 17.7% sand is present, meaning the soil can be prone to compaction if worked while wet.
Room for Soil Improvement
Organic matter stands at 2.53%, trailing the state average of 3.81%. The water capacity of 0.186 inches per inch is also slightly below the state benchmark, suggesting a need for careful moisture management.
Slow Drainage Challenges
Classified in hydrologic group D, these soils have a very slow rate of water transmission. Being moderately well drained, the land requires patience after heavy rains to avoid damaging the soil structure.
Cool Season Wins in Zone 5a
Zone 5a is ideal for cold-tolerant crops like broccoli, cabbage, and spinach. Adding compost can help boost the organic matter and improve the productivity of your local plot.
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
Moderately well drained
Water is removed somewhat slowly. May have a slowly permeable layer or seasonal water table.
Soil Profile
Dominant texture: Loam
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 Tama County have?
Tama County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 18% sand, 59% silt, and 23% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Tama County's soil acidic or alkaline?
Tama 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 Tama County?
Tama County has a dominant drainage class of "Moderately 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 Tama County's soil?
Based on Tama County's Loam texture, pH of 6.3, and Moderately 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 Tama County?
Tama 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: Tama County
Soil Verdict
Tama 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
Tama County closely matches the Iowa average hardiness conditions.
Planning your lawn? View lawn care data for Tama 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.