29 May Communication at the International Conference on Biogeochemistry of Trace Elements (2)
Glasshouse experiment to improve phytomanagement solutions for Cu-polluted mine soils
Marc Romero-Estonllo, Judith Ramos-Castro, Yaiza San Miguel, Beatríz Rodríguez-Garrido, Carmela Monterroso
International Conference on Biogeochemistry of Trace Elements, December, 2022, New York, USA
A glasshouse assay with trace element polluted soils from an old Cu mine ore (NW of Spain) which form part of the PhytoSUDOE network was set. The objective was to evaluate improvements induced by the following phytoremediation-related treatments. Three increasingly complex amendments alone or together with plant growth (Populus nigra L. alone and together with Tripholium repens L.) were tested. And three different rhizosphere bioinocula were applied (Plant Growth Promoting Bacteria (PGP), mycorrhiza (MYC), or mixed (PGP+MYC)). After 110 days of growth plants were collected and biomass was weighted and tree length measured. Plant tessue analysis were carried and physical-chemical soil properties were determined. Soil amendment, plant growth and bioinoculation, demonstrated to improve soil fertility and/or plant health within the time span of this study. Particularly, pH levels increased from 3 (highly acidic) to 5 (acidic) in the worst-case scenario, even reaching 7 (neutrality) in the best plots. Organic matter and pH increments were related with polluting metals’ bioavailability decrements. Plants grew the better both with the most complex amendment and the middle one, with few differences due to bioinoculation. Using the less complex amendment (just compost) beneficial effects of bioinoculants were more observable, although plants didn’t thrive very well. On unamended soils plants neither sprouted nor bloomed. The scheme assayed in this study is suitable for phytomanagement of these kinds of soils affected by mining activity. These findings should be tested now at a larger scale.