Shallow Geophysical Methods for Agricultural Land Characterization: Investigating Soil Physical Parameters for Precision Farming in Ciumbuleuit

Abstract This study addresses the agricultural challenge of effectively applying fertilizer in mountainous regions, focusing on the Ciumbuleuit sub-district in Punclut, West Bandung Regency. To improve agricultural practices and optimize soil water content, Electrical Resistivity Tomography (ERT) or generally known as DC-Resistivity and Electromagnetic Induction (EMI) were employed to assess variations in electrical resistivity and conductivity near the surface. ERT data were acquired using the Wenner configuration with a 0.5 m electrode spacing, while EMI data were collected using vertical mode and horizontal mode to determine subsurface conductivity. Measurements were consistently taken along six lines within a designated rectangular area. EMI maps revealed varying depths of investigation (0.38 m, 0.75 m, and 1.5 m), indicating low resistivity levels (0.1 – 58.9 Ωm) influenced by soil conditions. Conversely, ERT profiles displayed high-resistivity spots near the surface, with values ranging from 100 to 200 Ωm, and layers of low resistivity, with values ranging from 0.1 to 58.9 Ωm. The dry surface and low water content in the soil contributed to low conductivity and high resistivity values across the area. However, at depths greater than 0.38 m, high conductivity and low resistivity were observed, indicative of mid-water content soils ranging from clay to sandy compositions. These findings suggest a need for soil hydration through water and/or fertilizer application to optimize agricultural productivity.