Phytoremediation experiments in site S3 (Borralha mine, Portugal)

Phytoremediation experiments in site S3 (Borralha mine, Portugal)

The Borralha mine (PhytoSUDOE´s site 3) integrates soils with high trace elements concentrations that can benefit from the application of phytotechnologies. In this context, energy crops with phytoremediation capacity such as sunflower (Helianthus annuus) and poplar (Populus sp.), which have a high potential for success in adapting to soils of this nature, as well as bringing economic value, were selected. Rooted cuttings of Populus sp. were transplanted to field in April and sunflower was sowed in May 2017.

Foto1The inoculation of microorganisms such as mycorrhizal fungi (MF) and plant growth promoting bacteria (PGPB) that stimulate crop growth may benefit these plants by reducing the stress promoted by the contamination. Their application (technique known as bioaugmentation) in such conditions is being evaluated in some plots. The selected MF inocula and PGPR have shown positive results in previous similar contexts.

Other agronomic techniques such as intercropping with alfalfa and clover were integrated in the establishment of some of the plots in order to determine the increase organic matter and nutritive status of soil and the promotion of the biological activity.

In summary, eight treatments are being tested in the field: 1) monoculture of Populus (non-inoculated); 2)  monoculture of Populus (inoculated); 3) monoculture of sunflower (non-inoculated); 4) monoculture of sunflower  (inoculated); 5) intercropping with Populus and alfalfa (non-inoculated); 6) intercropping with Populus and alfalfa (inoculated); 7) intercropping with sunflower and clover (non-inoculated); 8) intercropping with sunflower and clover (inoculated).