The potential of Blepharidium guatemalense for nickel agromining in Mexico and Central America

Abstract

The aim of this study was to assess the potential of the woody nickel hyperaccumulator species Blepharidium guatemalense (Standl.) Standl. for agromining in southeastern Mexico. Pot trials consisting of nickel dosing (0, 20, 50, 100, and 250 mg Ni kg⁻¹), and synthetic and organic fertilization were conducted. Field trials were also undertaken with different harvesting regimes of B. guatemalense. Foliar nickel concentrations increased significantly with rising nickel additions, with a 300-fold increase at 250 mg Ni kg⁻¹ treatment relative to the control. Synthetic fertilization strongly increased nickel uptake without any change in plant growth or biomass, whereas organic fertilization enhanced plant shoot biomass with a negligible effect on foliar nickel concentrations. A 5-year-old stand which was subsequently harvested twice per year produced the maximum nickel yield tree⁻¹yr⁻¹, with an estimated total nickel yield of 142 kg ha⁻¹yr⁻¹. Blepharidium guatemalense is a prime candidate for nickel agromining on account of its high foliar Ni concentrations, high bioconcentration (180) and translocation factors (3.3), fast growth rate and high shoot biomass production. Future studies are needed to test the outcomes of the pot trials in the field. Extensive geochemical studies are needed to identify potential viable agromining locations. Novelty Statement Our research team is a pioneer in the discovery of metal hyperaccumulator plants in Mesoamerica with at least 13 species discovered in the last 2 years. This study is the first to assess the potential of nickel agromining (phytomining) in Mexico (and in all the American continent), using one of the strongest nickel hyperaccumulators reported so far. The promising results of this study are the basis for optimal agricultural management of Blepharidium guatemalense.

Keywords:

• Agronomy
• fertilization
• hyperaccumulation
• neotropics
• Ni yield
• phytomining

Acknowledgments

The authors acknowledge the Centre National de la Recherche Scientifique (CNRS) in France through the X-LIFE Research Program for their financial support. The first author thanks the Consejo Nacional de Ciencia y Tecnología (CONACyT) in Mexico for PhD funding. This work was partly supported by the French National Research Agency through the national program “Investissements d'avenir” with the reference ANR-10-LABX-21 -RESSOURCES21. The authors convey their sincere gratitude to Biol. Jorge A. Ramírez and all the students from the Universidad Tecnológica de la Selva (UTS, Unidad Académica de Crucero San Javier) for their substantial contribution to this research through their brilliant projects and field work. Acknowledgements to all the technicians from LSE for their valuable help to finish the analysis in the laboratory.

Disclosure statement

The authors declare that there is no conflict of interest. The content of the manuscript has not been published or submitted for publication elsewhere in any language. All authors have contributed significantly to the realization of the manuscript in different ways.