Evaluation of the phytostabilisation efficiency in a trace elements contaminated soil using soil health indicators

Area of Science:

• Environmental Science
• Soil Science
• Ecotoxicology

Background:

• Mine soils often exhibit high concentrations of trace elements (TEs), posing significant environmental and ecological risks.
• Assessing soil health recovery requires integrative methodologies evaluating microbiological, ecotoxicological, and physicochemical parameters.
• Phytostabilisation is a promising remediation strategy for contaminated soils, particularly in nutrient-poor environments.

Purpose of the Study:

• To evaluate the efficiency of a phytostabilisation strategy for remediating mine soil contaminated with trace elements.
• To assess the impact of amendments (compost, pig slurry, lime) and a halophytic shrub (Atriplex halimus L.) on soil health parameters.
• To establish a novel, integrative methodology for assessing soil recovery.

Main Methods:

• A 2.5-year field phytostabilisation experiment was conducted on mine soil.
• Amendments included olive mill-waste compost, pig slurry, and hydrated lime, with Atriplex halimus L. as the test plant.
• Soil and soil solution parameters (microbiological, ecotoxicological, physicochemical) were monitored in situ.

Main Results:

• Amendments increased soil pH and reduced trace element availability.
• Organic amendments (compost, pig slurry) promoted sustainable vegetation cover and stimulated soil microbial biomass, activity, and functional diversity.
• Direct and indirect soil toxicity were reduced, indicating lower associated environmental risks.

Conclusions:

• Phytostabilisation using compost and pig slurry combined with Atriplex halimus L. is an effective strategy for semi-arid mine soils.
• This approach improves soil health by enhancing habitat function, reactivating biogeochemical cycles, and reducing trace element dissemination.
• The study demonstrates an integrative methodology for assessing soil remediation success.