A Dominant Soil Parent Material Map for Indiana Derived From SSURGO Data.

The parent materials from which soils form carry with them many accessory characteristics that allow soil scientists to predict other soil properties. Many soils in Indiana have formed in two, and sometimes even three, distinctly different parent materials. We defined a set of 18 “dominant soil parent material” classes for Indiana (usually based on the lower-most parent material in the pedon) and assigned each soil series in the state to one of these classes. We then assigned a soil parent material class to each soil map unit in the SSURGO database based on the dominant soil series in the map unit. In this way, we have been able to create a dominant soil parent material map for the entire state. By overlaying the dominant soil parent material map onto a 5 meter digital elevation model (DEM), we are able to “see” the soil geomorphology of the state in unprecedented detail. We are incorporating this and other maps derived from the SSURGO dataset into our crop, soil, and environmental science courses using a “teaching with GIS” approach.