Jefferson County Soil Data
Jefferson County, Iowa
USDA SSURGO / PHZMAvg pH
6.2
Texture
Silt Loam
Drainage
N/A
Organic Matter
2.6%
Hydrologic Group
N/A
Data Story
About Soil in Jefferson County, Iowa
Jefferson's Acidic Soil Profile
Jefferson County has an average pH of 6.18, making it significantly more acidic than the national median of 6.5. While local classification data is limited, this acidity level often requires lime applications to optimize crop yields.
High Silt for High Retention
With a high silt content of 56.8% and 25.2% clay, these soils are heavy and retain nutrients exceptionally well. The low sand content of 18.0% means the soil is less prone to rapid leaching but can be slower to dry out.
Meeting the State Standard
The available water capacity of 0.195 in/in perfectly matches the Iowa state average. Though organic matter stands at 2.55%, the soil provides a reliable foundation for the region's diverse agricultural needs.
Moisture Management for Growers
Standardized drainage class data is unavailable for this specific area, but the high clay and silt percentages point to high water retention. Growers should monitor soil moisture closely to ensure proper aeration for root systems.
Garden Success in Zone 5b
Located in USDA Hardiness Zone 5b, Jefferson County is ideal for a variety of fruit trees and hearty vegetables. Plant some apple trees or start a berry patch to take advantage of this moisture-retentive soil.
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: Silt 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 Jefferson County have?
Jefferson County's soil is classified as Silt Loam. This indicates the relative proportions of sand, silt, and clay — 18% sand, 57% silt, and 25% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Jefferson County's soil acidic or alkaline?
Jefferson 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 Jefferson County?
Drainage class data is not currently available for Jefferson County.
What crops or plants grow well in Jefferson County's soil?
Based on Jefferson County's Silt Loam texture, pH of 6.2, and drainage class, the soil is well suited for vegetables, grains, and most field crops, row crops and vegetable gardens.
What USDA soil order is found in Jefferson County?
The dominant USDA soil order for Jefferson County is not currently available in our dataset.
Soil & Planting Advisory: Jefferson County
Soil Verdict
Jefferson County is in USDA hardiness zone 5b, a cold climate zone. where winter lows can reach -15°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
Jefferson County closely matches the Iowa average hardiness conditions.
Planning your lawn? View lawn care data for Jefferson 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.