Data for soil chloride used to identify areas of elevated soil salinity around the Mersehead Nature reserve, SW Scotland. Samples were collected in September – November 2022 and analysed to compare field methods for identification of areas of increased soil salinity. 
The chloride concentration of the samples was analysed by four field methods: A bench-top chloride analyser (MkII Chloride analyser, Sherwood. Abbreviated as "CA"), a novel Digital Image Colorimetry method using colorimetric test strips (Abbreviated as "DImC"), titration test strips (Quantab, Hach. Abbreviated as "TS"), and solution extract conductivity (HI98129, Hanna Instruments. Abbreviated as "Cext"). 
In addition to the methods analysing soil extracts, a direct soil conductivity instrument was also used (HydraGo, Stevens. Abbreviated as "Csoil").
Additional data included is the soil moisture content by standard drying method, soil moisture estimated by the HydraGo probe, calibration and quality control data for each of the methods mentioned above, and results of the analysis of chloride in a certified reference material.