About SoilByCounty

Data Source: USDA SSURGO

All soil data on this site comes from the USDA Soil Survey Geographic (SSURGO) Database, maintained by the Natural Resources Conservation Service (NRCS). SSURGO is the most detailed soil survey dataset available in the United States.

The data is accessed through the USDA Soil Data Access (SDA) web service, which provides programmatic access to the official soil survey information.

Methodology

For each county, we aggregate soil properties across all map units weighted by their area coverage. This produces county-level averages for pH, organic matter, sand/silt/clay percentages, available water capacity, and hydraulic conductivity.

The “dominant series” is the soil series that covers the largest percentage of a county's area. Texture class is determined using the USDA texture triangle based on sand, silt, and clay percentages.

Limitations

• County-level averages may mask significant local variation in soil properties.
• This data should not replace on-site soil testing for agricultural, construction, or landscaping decisions.
• Some counties may have incomplete SSURGO coverage, particularly in urban areas or federal lands.
• Soil properties can change over time due to land use, erosion, and other factors.

E-E-A-T Transparency

SoilByCounty is part of the ByCounty Network, a data platform that transforms free government datasets into accessible, county-level reports. We do not generate or estimate data — all values come directly from official USDA sources. Our role is presentation and accessibility.