Comparing EM38 and Profiler-EMP400 for the delineation of homogeneous management zones within agricultural fields

The improvement in crop yield, both in quantity and quality, depends on the adoption of appropriate management strategies for the agronomic and irrigation practices. The adoption of site-specific (SS) management practices is fundamental, not only to improve crop yield, but also for a more efficient use of resources, increasing the environmental sustainability of the agricultural production The SS management requires the delineation of sub-regions with similar yield limiting factors or similar soil properties affecting yield (Site Specific Management Units – SSMU). It is a common practice in precision agriculture (PA) to characterize the spatial variability of soil properties, measuring the soil electrical conductivity through non-invasive electro-magnetic (EM) sensors to obtain high-resolution soil maps for the delineation of SSMUs. Because of the expanding use in the future of the multi-frequency EM sensors in order to more effectively assess the soil variability, the objective of this work is to compare the measurements collected by Geonics EM38 (the most widely used EM sensor in PA) and GSSI Profiler-EMP400 (a multi-frequency EM sensor) in order to assess their reliability to delineate SSMUs. The data from 2-D electrical resistivity imaging were used to compare the response of the two different sensors to soil variability.