A team of USDA personel surveyed some of my fields with Ground Penetrating Radar. Pictured (right) is the device that was used and the map that was created. This technology is being tested as a possible way to learn more about the 4 feet of the soil structure. The following is an indepth description by James A. Doolittle, Research Soil Scientist USDA-NRCS-NSSC of what Ground Penetrating Radar does.

"In this area of Glenelg soil, most of the variation in EMI response is in the surface layers. The deeper-sensing (0 to 1.5 m) vertical dipole measurements are lower and less variable. I suspect that this response is derived principally from the meter reading a larger column of saprolite in this orientation. The shallower-sensing (0 to 75 cm) horizontal dipole measurements are responding to differences principally in the clay and moisture content of the A and Bt horizons.

As the highest readings were in the more sloping southwest portion of the field, the depth to the argillic horizon may be shallower, the argillic horizon may have a slightly higher clay content, and/or the surface layers may be heavier.

Low readings in the horizontal dipole orientation are attributed to shallower depths to saprolite or thicker surface layers and deeper depths to the argillic horizon.

Patterns look very good in the horizontal dipole orientation. This is good as these readings should be associated with crop response.