Carter County Soil Data
Carter County, Montana
USDA SSURGO / PHZMAvg pH
7.3
Texture
Loam
Drainage
N/A
Organic Matter
1.8%
Hydrologic Group
N/A
Data Story
About Soil in Carter County, Montana
Carter County's Moderate Alkaline Soil
The soil in Carter County has an average pH of 7.26, which is higher than the national median of 6.5. This level is slightly more neutral than the Montana state average of 7.43, making it relatively versatile for many regional crops. This slight alkalinity supports nutrient availability for local forage and grains.
A Balanced Textural Blend
The soil consists of 37.5% sand, 35.8% silt, and 26.6% clay, creating a well-distributed mixture. This balance allows for decent drainage while the clay content helps retain enough moisture for plant roots. It provides a stable foundation that is neither too heavy to work nor too loose to hold nutrients.
Managing Efficiency and Organic Matter
At 1.85%, the organic matter content is below the national average of 2.0% and the state average of 2.54%. The available water capacity of 0.161 in/in also sits just under the state benchmark of 0.165 in/in. Supplementing with organic materials can help boost these numbers and improve overall crop resilience.
Local Hydrology and Water Management
While specific drainage classes are not recorded, the balanced sand and clay mix typically supports steady infiltration. Farmers should monitor fields for pooling, especially given the county's specific clay percentage. Understanding how your specific plot handles runoff is essential for effective irrigation planning.
Grow Resilient Crops in Zone 4b
Carter County falls into USDA Hardiness Zone 4b, requiring plants that can endure deep winter freezes. This environment is ideal for wheat, flax, and hardy native grasses. Start your garden with cold-season staples like carrots and onions for the most reliable results.
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: 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 Carter County have?
Carter County's soil is classified as Loam. This indicates the relative proportions of sand, silt, and clay — 37% sand, 36% silt, and 27% clay. Loamy soils hold moisture well and support a wide range of plants.
Is Carter County's soil acidic or alkaline?
Carter County's soil has a pH of 7.3, which is near neutral. This range is ideal for most garden plants and field crops.
What is the drainage class for Carter County?
Drainage class data is not currently available for Carter County.
What crops or plants grow well in Carter County's soil?
Based on Carter County's Loam texture, pH of 7.3, 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 Carter County?
The dominant USDA soil order for Carter County is not currently available in our dataset.
Soil & Planting Advisory: Carter County
Soil Verdict
Carter County is in USDA hardiness zone 4b, a cold climate zone. where winter lows can reach -25°F. Soils here experience deep freeze cycles that can disrupt structure, kill shallow roots, and slow microbial activity for months each year.
Planting Guidance
Focus on cold-hardy perennials, native grasses, and conifers. The short growing window favors plants with low heat requirements. 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
Deep winter freezing can create soil heaving that pushes shallow-rooted plants out of the ground; add 3-4 inches of organic mulch each fall. Soil drainage is critical — frozen, waterlogged soil kills roots faster than cold alone. When soil temperatures drop below freezing, microbial nitrogen cycling stops; spring fertilization is more effective than late-fall application.
Regional Context
Carter County closely matches the Montana average hardiness conditions.
Planning your lawn? View lawn care data for Carter County on LawnByCounty.com →
Other Counties in Montana
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.