The resistance of a grounding rod is largely determined by the conductivity of the soil layer closest to the rod electrode. By replacing the soil layer using another layer that has a smaller resistivity, the grounding rod resistance value can be significantly reduced. Biochar and fly-ash additives with lower resistivity than the soil can be used as a substitute layer to reduce the resistance value of the grounding rod. As a filler layer, biochar and fly-ash will be mixed in several compositions. A certain sinusoidal current with a frequency variation of up to 50kHz is injected into the grounding rod arrangement for each biochar and fly-ash composition, the voltage between the rod electrode and the auxiliary electrode is measured and the response is determined. The grounding rod response with a certain frequency can be determined from the recording of current and voltage waves on a two-channel oscilloscope. The grounding rod's response at a certain frequency can exhibit resistive, capacitive, or inductive properties.