| Summary: | Cadmium (Cd) is a non-essential heavy metal naturally occurring in the earth’s crust ordue to
anthropogenic activity. The presence of thismetal in cacao farmsoils represents a significant issue as levels
are now regulated in products derived from cacao beans (Theobroma cacao L.). Several strategies have
been proposed to measure cadmium levels; however, little is known regarding in situ non-destructive
and time e cient techniques to analyze Cd contents in both cacao topsoils and subsoils, particularly
nearby the root system. Therefore, this research aims to integrate the physical property of soil
resistivity to Cd content in cacao soils. Cd hot spots are estimated from resistivity measurements
using a two-dimensional electrical resistivity tomography (2D-ERT) technique and correlated to Cd
determination using inductively coupled plasma optical emission spectrometry (ICP-OES). To assess
the dynamics of soil Cd content the correlation is discussed with other physical chemical parameters
of soils (pH, organic matter, Ca, Fe, and P). The study was performed in 27 cacao farms in Colombia.
A farm in Santander district proved to have the highest level of Cd using the correlated techniques
(2.76 mg kg�����1 Cd and 1815 Ohm m) followed by farms in Boyacá and Arauca districts (2.6 and
0.66 mg kg�����1 Cd, related to 1616 and 743 Ohm m, respectively). A high correlation between 2D-ERT
and Cd determination (R2 = 0.87) was found. The discussion regarding the soil parameters analyzed
suggests that the 2D-ERT technique could be used as a preliminary approach to explore Cd distribution
in cacao soils.
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