Correlation Dates for Soil Survey Reports
| Updated:
Author: Bradley Miller
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This map illustrates the correlation years for soil survey reports by county in Iowa. A soil correlation date indicates the year soil names and descriptions were officially approved for a given county’s soil survey. These dates reflect the versioning of soil data used for classification, mapping, and interpretation purposes. Updates may impact interpretations in land use, conservation, and development planning.
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Source:
Prepared by Gerald A. Miller and Thomas E. Fenton, Emeritus Professors of Agronomy
Iowa State University, Ames, Iowa 50011
As of March 2012
Interpretation:
Counties with more recent correlation dates (1998–present, shown in blue) reflect updated soil classification standards and improved data quality. Older correlation dates may lack modern interpretations, hydric soil updates, or revised mapping based on newer technologies like LiDAR and digital elevation models.
Resolution:
County-level static image showing approved correlation years
Suggested Use:
Useful for determining the currency and reliability of soil data when planning land use projects, conservation strategies, or field studies. Helps researchers and practitioners understand when the last major soil classification effort occurred for a given area.
References:
Miller, G.A., and Fenton, T.E. (2012). Soil Survey Correlation Dates by County. Iowa State University, Department of Agronomy.