GT1 (Leader INRA, other partners: ALL)

GT1 (Leader INRA, other partners: ALL)

GT1 contributes to establishing a network of phytomanaged contaminated/degraded sites within the SUDOE region to evidence the efficiency of phytotechnologies for ecologically remediating soils and enhancing soil functions and ecosystem services. GT1 is based on 3 main objectives at all sites (all partners are involved):

  • risk assessment
  • option appraisal and
  • remediation strategy.

The final established PhytoSUDOE network including a brief description and the strategy to be developed in PhytoSUDOE can be found here.

The main challenge confronted by GT1 during the first year of the project implementation was the establishment of the transnational network of contaminated or degraded field sites. Based on preliminary and current studies, and including data on the total concentrations of trace metals and organic contaminants in the soils, the sites for setting up the experimental plots were selected in the eight main field sites. Perimeter fences were installed at each site (when necessary), field work was carried out to prepare the surface area and an informative poster was mounted at each site with information targetting the general public related to the objectives and activities being carried out in the experimental plots. In the case of site S5 of Ariñez (Alava, ES), two study areas were established: S5a (potentially contaminated / degraded soil) and S5b (potentially contaminated soil).

The partners responsible for the management of the eight main field sites carried out an initial soil sampling campaign. Samples of both untreated soils and soils under phytomanagement were collected. The standard methods (Afnor / DIN / ISO / UNE) and procedures recommended by the European project Greenland (2015) are being used to obtain a harmonized dataset for soil characterization: soil pH, soil texture (5 fractions), density, organic C and total N, organic matter (detailed characterization of soil organic matter in GT4), extractable P (Olsen), CEC (cobalthexamine method at soil pH) and exchangeable cations, carbonates, water retention capacity, etc. Special attention has been paid to the bioavailability of trace elements and organic pollutants in soils. For the characterization of the organic contaminants, an indepth analysis was made determining volatile aromatic compounds, phenols, polycyclic aromatic hydrocarbons (PAH), volatile organohalogen compounds, chlorobenzenes, chlorophenols, polychlorinated biphenyls (PCB), chlorinated pesticides and hydrocarbons. The presence of organic contaminants was found to be significant in three of the 8 selected sites (S1, S2 and S5b). The physico-chemical parameters will help explain soil contaminant behaviour and exposure, the initial state of biodiversity and soil functions (GT2, 4), and to select the most viable phytomanagement options (GT1, 3).

Phytotoxicity tests were carried out by collecting soil samples in situ from the different sites. To evaluate the phytotoxicity, tests will be carried out with lettuce and dwarf beans, according to ISO 17126: 2005; determination of root biomass and aerial parts; shoot ionome (including TE concentrations); bioconcentration and translocation factors; comparison of labile and reactive fractions of TE in soil. Greenhouse-scale trials were also carried out to evaluate phytotoxicity in soils contaminated with hydrocarbons and their attenuation by inoculating plants with plant growth promoting bacteria (PGPB).

During the second year the tasks of WG1 focused, above all, on the generation of conceptual models, and the characterization of the soil samples collected at the beginning of the project for basic physical-chemical properties, bioavailability of pollutants and risk assessment. In addition, the evaluation of the appropriate phyto-management options for the different sites and the planning of monitoring and maintenance operations were carried out. In the different sites, activities such as agronomic and contaminant characterization, biometric and physiological characterization of native vegetation and crops (herbaceous or woody), characterization of activity, biomass and microbial functional biodiversity and identification of macro- and meso-fauna was achieved in order to determine the toxicological risks and identify optimum phytomanagement strategies for each sites.

The final months of the project were devoted to analyzing the results obtained and preparing a “Best Practices Guide for the phytomanagement of soils contaminated with metals / metalloids: risk assessment and phytomanagement and remediation strategies”.

In October, 2018, PhytoSUDOE officially ended. The Project deliverables were finalized along January-February, 2019, including the Layman report and the project’s video that were uploaded to the webpage’s news section (blog). Other relevant publications can be accessed also in the web along with the presentations (PDF) of the series of events organized by PhytoSUDOE. This website will be online until 2023.