Search

Graphical abstract The ability of tobacco (Nicotiana tabacum L. cv. Badischer Geudertheimer) for phytomanaging and remediating soil ecological functions at a contaminated site was assessed with a potted soil series made by fading an uncontaminated sandy soil with a contaminated sandy soil from the Borifer brownfield site, Bordeaux, SW France, at the 0%, 25%, 50%, 75%, and 100% addition rates. Activities of sandblasting and painting with metal-based paints occurred for decades at this urban brownfield, polluting the soil with metal(loid)s and organic contaminants, e.g., polycyclic aromatic hydrocarbons, in addition to past backfilling. Total topsoil metal(loid)s (e.g., 54,700 mg Zn and 5060 mg Cu kg−1) exceeded by seven- to tenfold the background values for French sandy soils, but the soil pH was 7.9, and overall, the 1M NH4NO3 extractable soil fractions of metals were relatively low. Leaf area, water content of shoots, and total chlorophyll (Chl) progressively decreased with the soil contamination, but the Chl fluorescence remained constant near its optimum value. Foliar Cu and Zn concentrations varied from 17.8 ± 4.2 (0%) to 27 ± 5 mg Cu kg−1 (100%) and from 60 ± 15 (0%) to 454 ± 53 mg Zn kg−1 (100%), respectively. Foliar Cd concentration peaked up to 1.74 ± 0.09 mg Cd kg−1, and its bioconcentration factor had the highest value (0.2) among those of the metal(loid)s. Few nutrient concentrations in the aboveground plant parts decreased with the soil contamination, e.g., foliar P concentration from 5972 ± 1026 (0%) to 2861 ± 334 mg kg−1 (100%). Vulnerability to drought-induced embolism (P50) did not differ for the tobacco stems across the soil series, whereas their hydraulic efficiency (Ks) declined significantly with increasing soil contamination. Overall, this tobacco cultivar grew relatively well even in the Borifer soil (100%), keeping its photosynthetic system healthy under stress, and contaminant exposure did not increase the vulnerability of the vascular system to drought. This tobacco had a relevant potential to annually phytoextract a part of the bioavailable soil Zn and Cd, i.e., shoot removals representing here 8.8% for Zn and 43.3% for Cd of their 1M NH4NO3 extractable amount in the potted Borifer soil. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-021-16411-y.

In situ stabilization of Cd, Pb, and Zn in an Austrian agricultural soil contaminated by atmospheric depositions from a smelter plant was assessed with a pine bark chip-derived biochar, alone and in combination with either compost or iron grit. Biochar amendment was also trialed in an uncontaminated soil to detect any detrimental effect. The pot experiment consisted in ten soil treatments (% w/w): untreated contaminated soil (Unt); Unt soil amended with biochar alone (1%: B1; 2.5%: B2.5) and in combination: B1 and B2.5 + 5% compost (B1C and B2.5C), B1 and B2.5 + 1% iron grit (B1Z and B2.5Z); uncontaminated soil (Ctrl); Ctrl soil amended with 1 or 2.5% biochar (CtrlB1, CtrlB2.5). After a 3-month reaction period, the soil pore water (SPW) was sampled in potted soils and dwarf beans were grown for a 2-week period. The SPW Cd, Pb, and Zn concentrations decreased in all amended-contaminated soils. The biochar effects increased with its addition rate and its combination with either compost or iron grit. Shoot Cd and Zn removals by beans were reduced and shoot Cd, Pb, and Zn concentrations decreased to common values in all amended soils except the B1 soil. Decreases in the SPW Cd/Pb/Zn concentrations did not improve the root and shoot yields of plants as compared to the Ctrl soil.

International audience; Brownfield surface is expanding in Europe, but as often abandoned or underused, these areas become refuge for microbial, faunal and floral biodiversity. However, brownfield sites are generally contaminated, likely posing severe environmental risks. At a former wood preservation site contaminated with Cu, we evaluated the efficiency of compost and dolomitic limestone incorporation into the soil, followed by revegetation with Cu-tolerant grassy species, as a phytomanagement option to increase vegetation cover and plant diversity while reducing pollutant linkages. 7 years of phytomanagement enhanced natural revegetation through the improvement of soil physicochemical properties, particularly with compost-based amendments. The compost incorporation increased soil Cu solubility; however, no increment in Cu availability and a reduction in Cu-induced phytotoxicity were observed with the compost. The improved soil nutrient availability and the soil phytotoxicity mitigation in compost-amended soils facilitated over the 7 years the growth of beneficial plant colonists, including leguminous species, which can potentially promote essential soil functions. Soil treatments did not affect Cu uptake and translocation by plants and shoot Cu levels indicated no risk for the food chain. Overall, a long-term phytomanagement combining an initial amendment of compost and dolomitic limestone with the cultivation of Cu-tolerant grassy populations can ameliorate such Cu-contaminated soils, by mitigating risks induced by Cu excess, ultimately allowing the development of a meadow that can provide ecological and economic benefits in terms of ecosystem services.Agrostis capillaris; Agrostis gigantea; Metal pollution; Organic amendments; Phytotoxicity; Phytoremediation

The rapid increase of the world population constantly demands more food production fromagricultural soils. This causes conflicts, since at the same time strong interest arises on novel bio-based products from agriculture, and newperspectives for rural landscapes with their valuable ecosystemservices. Agriculture is in transition to fulfill these demands. In many countries, conventional farming, influenced by post-war food requirements, has largely been transformed into integrated and sustainable farming. However, since it is estimated that agricultural production systems will have to produce food for a global population that might amount to 9.1 billion by 2050 and over 10 billion by the end of the century, we will require an even smarter use of the available land, including fallow and derelict sites. One of the biggest challenges is to reverse non-sustainable management and land degradation. Innovative technologies and principles have to be applied to characterize marginal lands, explore options for remediation and re-establish productivity. With view to the heterogeneity of agricultural lands, it is more than logical to apply specific crop management and production practices according to soil conditions. Cross-fertilizing with conservation agriculture, such a novel approach will provide (1) increased resource use efficiency by producing more with less (ensuring food security), (2) improved product quality, (3) ameliorated nutritional status in food and feed products, (4) increased sustainability, (5) product traceability and (6) minimized negative environmental impacts notably on biodiversity and ecological functions. A sustainable strategy for future agriculture should concentrate on production of food and fodder, before utilizing bulk fractions for emerging bio-based products and convert residual stage products to compost, biochar and bioenergy. The present position paper discusses recent developments to indicate how to unlock the potentials of marginal land. The authors are partners in the FACCE-SURPLUS project INTENSE and gratefully acknowledge financial support by the FACCE-JPI Programme SFS-05-2015: Strategies for crop productivity, stability and quality, grant number 652515.

Gentle remediation options (GRO), i.e. in situ stabilisation, (aided) phytoextraction and (aided) phytostabilisation, were implemented at ten European sites contaminated with trace elements (TE) from various anthropogenic sources: mining, atmospheric fallout, landfill leachates, wood preservatives, dredged-sediments, and dumped wastes. To assess the performance of the GRO options, topsoil was collected from each field trial, potted, and cultivated with lettuce (Lactuca sativa L.) for 48 days. Shoot dry weight (DW) yield, photosynthesis efficiency and major element and TE concentrations in the soil pore water and lettuce shoots were measured.GRO implementation had a limited effect on TE concentrations in the soil pore water, although use of multivariate Co-inertia Analysis revealed a clear amelioration effect in phytomanaged soils. Phytomanagement increased shoot DW yield at all industrial and mine sites, whereas in agricultural soils improvements were produced in one out of five sites. Photosynthesis efficiency was less sensitive than changes in shoot biomass and did not discriminate changes in soil conditions.Based on lettuce shoot DW yield, compost amendment followed by phytoextraction yielded better results than phytostabilisation; moreover shoot ionome data proved that, depending on initial soil conditions, recurrent compost application may be required to maintain crop production with common shoot nutrient concentrations.

International audience; A 2-year pot experiment was carried out to examine the aging effect of biochar (B), alone or combined with iron grit (Z), on Cu stabilization and plant growth in a contaminated soil (964 mg Cu kg− 1) from a wood preservation site. The experiment consisted in 3 soil treatments, either planted with Arundo donax L. (Ad) or Populus nigra L. (Pn): (1) untreated Cu-contaminated soil (Ad, Pn); (2) Unt + 1% (w/w) B (AdB, PnB), and (3) Unt + 1% B + 1% Z (AdBZ, PnBZ). After 22 months, the soil pore water (SPW) was sampled and roots and shoots were harvested. The SPW compositions at 3 and 22 months were compared, showing that the SPW Cu2 + concentration increased again in the PnB and PnBZ soils. Cultivation of A. donax enhanced the dissolved organic matter concentration in the SPW, which decreased its Cu2 + concentration but promoted its total Cu concentration in the Ad and AdB soils. Adding Z with B reduced both SPW Cu2 + and Cu concentrations in the pots cultivated by A. donax and P. nigra as compared to B alone. The B and BZ treatments did not enhance root and shoot yields of both plant species as compared to the Unt soil but their shoot Cu concentrations were in the range of common values.

International audience; Aided phytostabilization of a barren, alkaline metal(loid)-contaminated technosol developed on steel mill wastes, with high soluble Cr and Mo concentrations, was assessed in a pot experiment using (1) Ni/Cd-tolerant populations of Festuca pratensis Huds. , Holcus lanatus L. , and Plantago lanceolata L. sowed in mixed stand and (2) six soil treatments: untreated soil (UNT), ramial chipped wood (RCW, 500 m3ha−1), composted sewage sludge (CSS, 120 t DW ha−1), UNT soil amended with compost (5% w/w) and either vermiculite (5%, VOM) or iron grit (1%, OMZ), and an uncontaminated soil (CTRL). In the CSS soil, pH and soluble Cr decreased whereas soluble Cu, K, Fe, Mn, Mg, Ni and P increased. The RCW treatment enhanced soluble Fe, Mn, and Mg concentrations. After 15 weeks, shoot DW yield and shoot Cd, Cu, Fe, Mn, Mo, Zn, and Mg removals peaked for F. pratensis grown on the CSS soil, with lowest shoot Cr, Ni and Mo concentrations. Holcus lanatus only grew on the CTRL, UNT, and CSS soils and P. lanceolata on the CTRL soil. Best treatment, F. pratensis grown on the CSS soil, led to a dense grass cover but its shoot Mo concentration exceeded the maximum permitted concentration in forage.

International audience; Biomonitoring complements the physico-chemical analysis of environmental matrices, accounting for the subtle biological changes in organisms affected by exogenous chemicals. Here, the relationships between the concentrations of trace elements (TE) in the soil, soil-pore water and leaves of seven rooted macrophytes (Ranunculus acris L., Phragmites australis (Cav.) Trin. Ex Steud., Carex riparia Ehrh., Lythrum salicaria L., Iris pseudacorus L., Juncus effusus L., and Phalaris arundinacea L.) were investigated along an urban river – the Jalle d’Eysines River, France – with increasing TE contamination in riverbank soils, from its source to its confluence with the Garonne River. Copper, Zn, Cd, Cr, Pb, Ni, Mo and As were considered. Macrophytes were sampled in June 2011, at the peak of the growing season. For five species, a canonical correspondence analysis (CCA) was used to assess correlations between foliar TE concentrations and total TE concentrations in the soil. Along the Jalle d’Eysines River, P. australis and P. arundinacea are relevant biomonitors for soil Mo contamination. P. australis and C. riparia biomonitor soil Cd contamination, while R. acris is a relevant biomonitor of soil Ni contamination. Copper and Mo concentrations in the soil-pore water are monitored by, respectively P. arundinacea and P. australis.

Intra-specific variability of root biomass production (RP) of six rooted macrophytes, i.e. Juncus effusus , Phragmites australis , Schoenoplectus lacustris , Typha latifolia , Phalaris arundinacea , and Iris pseudacorus grown from clones, in response to Cu exposure was investigated. Root biomass production varied widely for all these macrophytes in control conditions (0.08 μM) according to the sampling site. Root biomass production of T. latifolia and I. pseudacorus in the 2.5–25 μM Cu range depended on the sampling location but not on the Cu dose in the growth medium. For P. australis , J. effusus , S. lacustris , and P. arundinacea , an intra-specific variability of RP depending on both the sampling location and the Cu-dose was evidenced. This intra-specific variability of RP depending on the sampling location and of Cu-tolerance for these last four species suggests that Cu constitutive tolerance for all rooted macrophytes is not a species-wide trait but it exhibits variability for some species.