Capability of amendments (biochar, compost and garden soil) added to a mining technosol contaminated by Pb and As to allow poplar seed (Populus nigra L.) germination

• Published in: Environmental monitoring and assessment 2019-07, Vol.191 (7), p.465-12, Article 465
• Main Authors: Nandillon, R., Lebrun, M., Miard, F., Gaillard, M., Sabatier, S., Villar, M., Bourgerie, S., Morabito, D.
• Format: Article
• Language: English
• Subjects: Agricultural sciences; Arsenic; Atmospheric Protection/Air Quality Control/Air Pollution; Body organs; Charcoal; Composting; Composts; Earth and Environmental Science; Ecology; Ecotoxicology; Environment; Environmental Management; Environmental monitoring; Environmental science; Environmental Sciences; Gardens & gardening; Germination; Heavy metals; Lead; Life Sciences; Mapping and Remedying Soil Pollution; Mesocosms; Metals; Mining; Monitoring; Monitoring/Environmental Analysis; Organs; Physicochemical processes; Physicochemical properties; Plant growth; Plant organs; Poplar; Populus nigra; Pore water; Revegetation; Seed germination; Seeds; Silviculture, forestry; Soil; Soil amendment; Soil contamination; Soil pollution; Soil properties; Soil stabilization; Soil study; Soil water; Topical Collection on Global Approaches to Assessing
• ISSN: 0167-6369; 1573-2959
• DOI: 10.1007/s10661-019-7561-6

The germination capacity of poplar seeds has never been studied in the context of metal(loid)-contaminated soils, even though poplars are present over a vast geographical area. In this study, black poplar seeds from the Loire Valley (France) were grown for 28 days in mesocosm on a heavily polluted soil that was subjected to different amendments. This phytomanagement process aimed to allow the revegetation of an As and Pb–contaminated mining soil by adding appropriate amendments, resulting in metal(loid) soil stabilisation and efficient plant growth. The objectives were to evaluate the effect of three amendments (garden soil, compost and biochar) when added alone or combined to a technosol on (i) the soil physicochemical properties, (ii) the mobility of As and Pb in the soil pore water (SPW), (iii) the capacity of poplar seeds to germinate and to grow and (iv) the metal(loid) distribution within the plant organs. The addition of amendments alone or combined allowed a 90% decrease in SPW Pb concentrations, while the arsenic concentrations were between 18 and 416 times higher. However, we were only able to obtain seed germination and plant growth on amended soils. These promising results will allow us to explore the use of such amendments in rehabilitating areas that are sources of significant metal(loid) dissemination, as well as allowing a natural plant recolonisation of these sites by seeds from the surrounding environment.