ORIGINAL RESEARCH article
Front. Soil Sci.
Sec. Soil Pollution & Remediation
Cadmium Distribution and Soil Properties Across Soil Orders Under Cacao (Theobroma cacao L.) Cultivation in the Peruvian Amazon
Provisionally accepted
- 1Instituto Nacional de Innovacion Agraria, La Molina, Peru
- 2Universidad Nacional de San Martin Tarapoto, Tarapoto, Peru
Select one of your emails
You have multiple emails registered with Frontiers:
Notify me on publication
Please enter your email address:
If you already have an account, please login
You don't have a Frontiers account ? You can register here
High cadmium (Cd) levels in Peru are limiting access to international markets that have implemented stricter thresholds for allowable concentrations in chocolate and its derivatives. This study aimed to analyse the distribution of cadmium profiles and their edaphic controls across different soil orders under cacao (Theobroma cacao L.) cultivation in the Peruvian Amazon. The research was conducted in three locations within two districts of the San Martín department, encompassing an area of 4,073.54 km². The study sites included the towns of La Unión and Nuevo San Martín in the Pólvora district (Tocache province) and the town of Perla Mayo in the Campanilla district (Mariscal Cáceres province). In each locality, ten 100 m² plots were selected, resulting in a total of 30 plots. Soil samples were collected by excavating pits measuring 1 × 0.8 m, with samples taken from two depth intervals: 0–30 cm and 30–60 cm. Total cadmium concentrations and key physicochemical parameters were then analysed. The soils in La Unión exhibited the highest average Cd concentrations at 0–30 cm depth (1.35 ± 0.21 mg/kg), while the lowest concentrations were recorded in Perla Mayo at the same depth (0.27 ± 0.25 mg/kg). Regarding soil classification, Entisols and Alfisols presented the lowest average Cd contents (0.66 ± 0.35 mg/kg and 0.15 ± 0.15 mg/kg, respectively). Among the evaluated soil properties, cation exchange capacity (CEC) and clay content were identified as the primary factors influencing cadmium levels, followed by soil pH. In conclusion, cadmium tends to accumulate in the surface horizons of fine-textured, acidic soils at each study site. The edaphic conditions in Perla Mayo appear to be the most favourable, showing minimal cadmium accumulation, and may serve as a reference for developing agricultural management strategies aimed at reducing cadmium uptake in cacao-growing soils.
Keywords: Inceptisol, physicochemical properties, heavy metal, principal components, Monoculture, Peru, Cacao
Received: 20 Aug 2025; Accepted: 31 Oct 2025.
Copyright: © 2025 Vallejos-Torres, Chuchon, Gaona-Jimenez, Cruz and Solórzano. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Geomar Vallejos-Torres, gvallejos@unsm.edu.pe
Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.