Submitted to: Ohio Geospatial Technology Conference for Agriculture and Natural Resource Applications
Publication Type: Other
Publication Acceptance Date: 11/2/2002
Publication Date: 3/24/2003
Citation: ALLRED, B.J., EHSANI, R., DANIELS, J.J. COMPARISON OF THREE NEAR-SURFACE GEOPHYSICAL METHODS USED AGRICULTURALLY TO MAP SOIL ELECTRICAL CONDUCTIVITY. OHIO GEOSPATIAL TECHNOLOGY CONFERENCE FOR AGRICULTURE AND NATURAL RESOURCE APPLICATIONS. 2002. Poster. Interpretive Summary:
Technical Abstract: Apparent soil electrical conductivity (ECa), mapped in situ with near-surface geophysical methods, can potentially be used to gauge spatial changes in soil fertility, since both are influenced by soil profile properties that include salinity, organic matter content, cation exchange capacity, grain size distribution, clay mineralogy, claypan/fragipan depth, etc. Electromagnetic induction and two different pulled electrode array resistivity methods were used to map ECa on two different Columbus, Ohio agricultural test plots having fine-grained glacially derived soils. All three near-surface geophysical methods appeared to work equally well when evaluated on the two test plots. Although the average test plot ECa values differed between the three methods, spatial ECa patterns, when compared, were quite similar. In addition, changing field conditions were found to impact the magnitude of the ECa values but not their spatial pattern. Overall, these results suggest that comparable ECa maps can be obtained regardless of which near-surface geophysical ECa measurement method is used.