Preliminary study utilization of resistivity method to identify soil types for agricultural purposes

The purpose of this research is to identify the type of soil based on the value of soil resistivity as an alternative method besides the grain gradation test. The research was conducted using the geoelectric method and the grain gradation test as validating methods. We use the Wenner-Schlumberger configuration with the spacing of 0.5 m and a track length of 20 m at Sumbersari, Ambulu, and Pakusari areas. The results of the geoelectric data are used as the basis for sampling for the grain gradation test. The soil sample used on the gradation test was taken in the form of soil at a depth of topsoil and subsoil at a certain point from every observation line. The filter used in the grain gradation test is using a sieve with pan sizes 4, 10, 20, 35, 60, 100, 200 mm. The results of the geoelectric and grain gradation test showed that at locations 1, 2, and 3 the soil types were found in the topsoil and subsoil layers, namely regosol soil which was supported by the results of the grain gradation test, and resistivity method result, where the sand content in the soil type was >60%, it was categorized as regosol soil. Finally, by using this resistivity method, the soil type can be predicted, which can be used as a method to determine the type of soil for agricultural purposes.