Field Mapping Soil Conductivity to Delineate Dryland Saline Seeps with Four‐electrode Technique

Abstract

AbstractContinuing incidence of saline‐seep areas in the northern Great Plains dryland soils has created a need for detecting and delineating encroaching saline seeps before plant growth is affected. We evaluated the four‐electrode conductivity technique for field mapping surface and subsurface soil salinity under dryland conditions.Results indicated that the four‐electrode conductivity technique can be used successfully to quickly field map surface and subsurface soil salinity boundaries of existing and potential saline‐seep areas. This technique also depicted underground flow patterns of a shallow, saline ground water table.Maps of apparent bulk soil conductivity values (ECa) were used to locate the position of the recharge area in relation to the discharge (seep) area. While maps of discrete depth interval conductivity values (ECx) provided more precise information, the time required may not warrant the additional required calculations unless a portable programable calculator is available. Mapping soil salinity with the four‐electrode conductivity technique is easy, rapid, and relatively inexpensive. This technique provides information useful in making management decisions to prevent or alleviate a saline seep or other soil salinity problems.