Cadmium distribution in soils, soil litter and cacao beans: a case study from Colombia

Abstract

Cadmium is a toxic non-essential metal for almost all living systems. It is one of the biggest challenges for farmlands and the food chain because of its toxic effect on human health. This research aims to determine the Cd content in soils, litter and cacao beans, following the Cd fluxes within each cacao system using the two-dimensional electrical resistivity tomography technique. The study was carried out in four farms located in the Magdalena basin in Antioquia, Colombia. The farms showed a heterogeneity in relation to cacao cultivars, altitude, topography and geology. The soil cation electrical capacity, pH and soil organic matter levels, as well as the Al, Al 3+ H + , Ca, K, Mg and P contents were measured at different depths. Moreover, the Cd content was correlated to the resistivity values of samples taken in situ using ERT. Soil Al 3+ H + and the altitude of the farms fitted as the best predictors of the beans' Cd content. Furthermore, the Cd content in soils from the assessed farms ranged between 1.22 and 2.03 mg kg −1 . The Cd content in cocoa beans ranged from 0.07 to 1.44 mg kg −1 , with a value of 0.40 mg kg −1 on average. The resistivity values obtained in field showed a high correlation with the soil Cd content determined (R 2 = 0.82). The predictive tomography plots highlighted topsoil Cd dynamics between litter, amendments and fertilizers. Therefore, these results underlie the utility of the combined geophysical techniques and soil chemical properties including the analysis of fertilizer amendments to improve the understanding of Cd dynamic.

Bacterial Cadmium-Immobilization Activity Measured by Isothermal Microcalorimetry in Cacao-Growing Soils From Colombia

“…Figure 1 shows the location of sampling sites. Each sample consisted of a composite sample made by mixing soil samples from 20 farms within each of the (Gil et al, 2022). The soil type of cacao farms sampled from Arauca were classified as Typic Endoaquepts of Inceptisols (Bravo and Benavides-Erazo, 2020).…”

“…Soil pH was measured in each sample. The soil pH was assessed with a pH meter (Toledo, Spain) according to a previous method (Gil et al, 2022). The soil organic matter was quantified by atomic absortion spectrometry (Agilent Technologies, CA, United States).…”

“…In this study three soil origin were confirmed. The soil type from Antioquia belong to the subgroup Oxic Dystrudepts of Inceptisols with some presence of Cd-like rocky types mainly in the forms of "Antioqueño Batholites" (Gil et al, 2022). The soil type of cacao farms from Arauca were Typic Endoaquepts of Inceptisols, with low levels of clay content (1.15%), SOM (less than 3%), and lower patchy parent material in alluvial sediments in farms nears to the rivers (Bravo and Benavides-Erazo, 2020).…”

“…In previous studies in Central and South America (Chavez et al, 2015;Gramlich et al, 2018;Engbersen et al, 2019;Ramtahal et al, 2019), including Colombia (Gil et al, 2022), physical and chemical soil parameters, such as soil pH, soil organic matter (SOM) and the Cd values in soils have been identified as having a major influence on the final content of Cd in cacao beans. However, the role in situ of CdtB in translocation rates of the metal from soil to crop hast not been studied.…”

Cadmium‐tolerant bacteria: current trends and applications in agriculture

“…In farmland soils, the Cd content is due to geogenic conditions, however, maybe also due to human activities related to bad‐quality manures, amendments and fertilizer abuse (Gil et al . 2021 ), as well as to mining, oil pipelines, smelting, electroplating, irrigation using wastewater or Cd‐contaminated efflux water (Bolan et al . 2014 ).…”