The Use of EMI for Verification of Soil Variability.

The Southern High Plains portion of MLRA 77-C is being updated.  A portion of this area consists of sand dunes with inter-duneal soils.  This area was originally mapped as a miscellaneous land type.  For the update, these soils are being mapped at the order 2 or 3 level depending upon the land use.  It has been difficult separating the area into individual mapping units because o soil variability and map scale. Several 10-point transects were completed to identify map unit composition and soil series purity.  Because the distance between observations was fixed (50 m), map unit variability was not accurately captured. A DULEM 2M was transverse over the same transect as the observed sites.  A reading was recorded ever 2 seconds. This was repeated for three additional transects. The data were downloaded and divided into 5 ECa classes. The classes were compared to the auger observations and subsequently compared to map unites. Regrouping into three classes captured approximately 95 % of the soil variability.