“…An increase in bulk density implies an increase in the percentage of the total volume of soil occupied by its solid phase, and consequently, indicates soil compaction. If the tracer had been applied homogeneously throughout the entire soil volume, an increase in bulk density would have meant a higher concentration of tracer per soil volume, and therefore affecting the magnetic susceptibility intensity (Jimenez et al, 2017). However, this was not the case in the present experiments as the tracer was mixed only in a thin layer of subsurface soil (see earlier).…”