•Sugarbeet plants show tolerance to cadmium up to 225.8mg bioavailable Cd kg−1 soil.•Ni content in soil inhibited plant growth, and bioavailable concentration of 75.4mgkg−1 were lethal to plants.•Cd ...and Ni are accumulated in sugar beet tissues.
Sugarbeet (Beta vulgaris L.) was tested in a greenhouse pot experiment to evaluate its growth, tolerance ability and remediation potential to soils contaminated with cadmium (Cd) and nickel (Ni). Sugarbeet seeds were pre-germinated and four weeks after sowing the seedlings were transplanted to 36 pots. They were left to grow for 12 weeks and then aqueous solutions of nitrate salts of Cd and Ni were added to the soil. The applied treatments were: only Cd(NO3)2.4H2O addition in quantities (g) of Cd0:0, Cd0.5:0.5, Cd5:5, and Cd10:10; only Ni(NO3)2.4H2O addition in quantities (g) of Ni0:0, Ni1:1, Ni10:10, and Ni20:20; a combination of both salts in quantities (g) of Cd0+Ni0: 0+0, Cd0.25+Ni0.5: 0.25+0.5, Cd2.5+Ni5: 2.5+5, Cd5+Ni10: 5+10. At the end of the experiment, the determined DTPA-extractable metal concentrations in soil were up to 225.8mg Cd kg−1 and 75.4mg Ni kg−1. Under the Cd treatment, plant growth remained unaffected, with the exception of the leaves’ number, which differed significantly among control (Cd0) and highly (Cd10) treated plants on the last measurement date. Nickel affected sugarbeets growth and Ni20 was lethal to the plants. Under the combined Cd and Ni treatment, the toxicity symptoms were milder than in Ni treatment and only the Cd5+Ni10 treated plants were affected. The higher accumulation rate of Cd and Ni was recorded in the above-ground biomass, with beets also experiencing cadmium and nickel accumulation. Under Cd10 treatment, metal content reached 92.1mgkg−1 in the aboveground biomass and 14.3mgkg−1 in beets, while Ni concentrations under Ni10 treatment were up to 283.3mgkg−1 and 45.9mgkg−1 respectively. Under the combined Cd and Ni treatments, Cd concentrations were up to 172.5 and 76.7mgkg−1 in shoots and beets, respectively, while Ni was up to 467.8 and 289.7mgkg−1, respectively. Metal accumulation (mg per pot) in the single experiments followed the pattern Cd>Ni, mostly due to the higher biomass production in the Cd pots and the higher Cd mobilized content in the soil. In the combined Cd and Ni contamination, Ni accumulation was higher than the Cd accumulation, reflecting a preference by sugarbeet to absorb an ion with lower radius and higher electronegativity. Higher modified translocation factors (mTFs) were obtained for Ni, in the single experiments. In the combined experiment, the mTFs was reduced for both metals due to the combined accumulation of Ni and Cd. Sugarbeet can be considered an interesting candidate for Cd phytoextraction, favored by the biomass produced and accumulation observed but further studies should be conducted in order to evaluate the effect of the soil contamination on the bioethanol yield and quality.
This study deals with approaches for a social-ecological friendly European bioeconomy based on biomass from industrial crops cultivated on marginal agricultural land. The selected crops to be ...investigated are: Biomass sorghum, camelina, cardoon, castor, crambe, Ethiopian mustard, giant reed, hemp, lupin, miscanthus, pennycress, poplar, reed canary grass, safflower, Siberian elm, switchgrass, tall wheatgrass, wild sugarcane, and willow. The research question focused on the overall crop growth suitability under low-input management. The study assessed: (i) How the growth suitability of industrial crops can be defined under the given natural constraints of European marginal agricultural lands; and (ii) which agricultural practices are required for marginal agricultural land low-input systems (MALLIS). For the growth-suitability analysis, available thresholds and growth requirements of the selected industrial crops were defined. The marginal agricultural land was categorized according to the agro-ecological zone (AEZ) concept in combination with the marginality constraints, so-called ‘marginal agro-ecological zones’ (M-AEZ). It was found that both large marginal agricultural areas and numerous agricultural practices are available for industrial crop cultivation on European marginal agricultural lands. These results help to further describe the suitability of industrial crops for the development of social-ecologically friendly MALLIS in Europe.
The need of biofuels from biomass, including sustainable aviation fuel, without using agricultural land dedicated to food crops, is in constant demand. Strategies to intensify biomass production ...using mycorrhizal fungi, biostimulants and their combinations could be solutions for improving the cultivation of lignocellulosic plants but still lack well-established validation on metal-contaminated soils. This study aimed to assess the yield of Miscanthus x giganteus J.M. Greef & Deuter and Cannabis sativa L. grown on a metal-contaminated agricultural soil (11 mg Cd, 536 mg Pb and 955 mg Zn kg−1) amended with biostimulants and/or arbuscular mycorrhizal fungi, and the shoot Cd, Pb and Zn uptake. A pot trial was carried out with soil collected from a field near a former Pb/Zn smelter in France and six treatments: control (C), protein hydrolysate (a mixture of peptides and amino acids, PH), humic/fulvic acids (HFA), arbuscular mycorrhizae fungi (AMF), PH combined with AMF (PHxAMF), and HFA combined with AMF (HFAxAMF). Metal concentrations in the soil pore water (SPW), pH and electrical conductivity were measured over time. Miscanthus and hemp shoots were harvested on day 90. Both PH and PHxAMF treatments increased SPW Cd, Pb, and Zn concentrations (e.g. by 26, 1.9, and 22.9 times for miscanthus and 9.7, 4.7, and 19.3 times for hemp in the PH and PHxAMF treatments as compared to the control one, respectively). This led to phytotoxicity and reduced shoot yield for miscanthus. Conversely, HFA and HFAxAMF treatments decreased SPW Cd and Zn concentrations, increasing shoot yields for hemp and miscanthus. Shoot Cd, Pb, and Zn uptakes peaked for PH and PHxAMF hemp plants (in μg plant-1, Cd: 310–334, Pb: 34–38, and Zn: 232–309 for PHxAMF and PH, respectively), while lowest values occurred for PH miscanthus plants mainly due to low shoot yield. Overall, this study suggested that humic/fulvic acids can be an effective biostimulant for increasing shoot biomass production in a metal-contaminated soil. These results warrant further investigations of the HFAxAMF in field trials.
Display omitted
•Miscanthus and hemp grow well on a metal-contaminated soil.•Protein hydrolysate treatments increased Cd and Zn concentrations in the soil pore water.•Soil acidification and metal exposure induced by protein hydrolysate reduced miscanthus biomass.•Protein hydrolysate combined with mycorrhizae improved metal uptake by hemp.•Mycorrhizae-associated humic/fulvic acids improved hemp biomass.
Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. In the present study, eight experimental sites in three ...different climatic zones in Europe (Mediterranean, Atlantic and Continental), seven advanced industrial crop species giant reed (two clones), miscanthus (M. × giganteus and two new seed‐based hybrids), saccharum (one clones), switchgrass (one variety), tall wheatgrass (one variety), industrial hemp (three varieties) and willow (eleven clones), and six marginality factors alone or in combination (dryness, unfavorable texture, stoniness, shallow soil, topsoil acidity, heavy metal and metalloid contamination) were investigated. At each site, biophysical constraints and low‐input management practices were combined with prevailing climatic conditions. The relative yield of a site‐specific low‐input system compared with the site‐specific control was from small to large (i.e. from −99% in industrial hemp in the Mediterranean to +210% in willow in the Continental zone), due to the genotype‐by‐management interaction along with climatic variation between growing seasons. Genotype selection and improved knowledge on crop response to changing environmental, site‐specific biophysical constraint and input application has been detected as key to profitably grow industrial crops on marginal areas. This study may act to provide hints on how to scale up investigated cropping systems, through low‐input practices, under similar environmental and soil conditions tested at each site. However, further attention to detail on the agronomy of early plant development and management in larger multi‐year and multi‐location field studies with commercially scalable agronomies are needed to validate yield performances, and thereby to inform on the best industrial crop options.
Growing industrial crops on marginal lands has been proposed as a strategy to minimize competition for arable land and food production. This study can bring an advancement to knowledge on the suitability of certain industrial crops to marginal and contaminated soils to mitigate indirect land‐use change (i‐LUC) in accordance with the RED II and to meet the European Green Deal towards an EU climate neutral in 2050. It ultimately can assist to make general recommendations of the most appropriate crop and management options at the different regions, climates, soils and marginal land types.
The management of mine waste has become an urgent issue, especially in semi-arid environments. In this context, and with an aim to inhibit the oxidation of the sulfide tailings of the abandoned mine ...of Kettara in Morocco, a store-and-release (SR) cover made of phosphate mine waste (PW) was implemented. In order to guarantee its long-term performance, phytostabilization by local wild plant species is currently the most effective and sustainable solution. This study aimed to assess the growth performance and phytostabilization efficiency of five local wild plant species to grow on the SR cover made of PW. A field experiment was conducted for two growing seasons (2018 and 2019), without amendments and with the minimum of human care. PW and the aboveground and belowground parts of the studied plant species were collected and analyzed for As, Cd, Cu, Ni, and Zn. The bioconcentration factor (BCF) and translocation factor (TF) were also calculated. Despite the hostile conditions of the mining environment, the five plant species showed promising growth performances as follows: Atriplex semibaccata > Vicia sativa > Launaea arborescens > Peganum harmala > Asparagus horridus. The five plants showed high accumulation capacity of the trace elements, with the highest concentrations in belowground tissue. Principal component analysis distinguished A. semibaccata as having a high concentration of Cu and As, while Asparagus horridus had higher concentrations of Cd and Zn. In contrast, P. harmala, V. sativa, and L. arborescens demonstrated affinity regarding Ni. According to the BCF (<1) and TF (<1), these plant species could be used as effective phytostabilizers of the studied trace elements. The present study showed that local wild plant species have a great potential for the phytostabilization of PW, and could ensure the long-term efficiency of SR cover.
•The research work presents the long-term performance (17 years) of switchgrass grown on a marginal field in central Greece.•It was found that switchgrass could provide mean yields of 12kgDMha−1, ...averaged over all years and treatments.•Lowland varieties were more productive than the upland ones with a mean superiorly of 8%, averaged overall years and treatments. At the same time lowland varieties were more resistant to lodging when grown in the pedoclimatic conditions of central Greece.•From the fourth growing period and onwards when the nitrogen fertilization was gradually increased from 0 to 75 and 150kgN/ha the yields were also significant increased.•Lifetime higher than 15 years have been proved for switchgrass grown on marginal land (shallow soil with reduced fertility).
Switchgrass (Panicum virgatum L.) is a perennial grass that has been selected as a candidate bioenergy crop for USA in the early 80s, while the research in Europe started a decade later. A long-term study on switchgrass had been carried out (1998–2015) on a marginal area in Greece comparing five varieties (having lowland or upland ecotype) at increasing nitrogen fertilization rates (0, 75 and 150kgNha−1). Due to the successful establishment of the plantation quite satisfactory yields were recorded even at the establishment year (8.9MgDMha−1) and the ceiling yields were recorded in the 2nd year and came up to 20MgDMha−1. The under study lowland varieties (Alamo, Kanlow and Pangburn) were more productive compared to the upland varieties (Blackwell and CIR) with mean dry yields 12.37 and 11.39 Mgha−1, respectively and showed higher resistance to lodging. Among the five under study varieties, Alamo was the best performing giving an average yield of 12.7MgDMha−1, averaged over all treatments and years, while CIR was the least performing producing a corresponding average yield of 10.8MgDMha−1. From the fourth growing season and onwards significantly higher yields were recorded under increasing N fertilization up to 150kgNha−1 with an average yield of 13.9MgDMha−1 (150kgN/ha) over all varieties and years. The corresponding yields for the other two tested nitrogen rates (0 and 75kgN/ha) were 10.31 and 11.69MgDMha−1, respectively.
•Extraction of essential oil of Jatropha curcas L. grown under Moroccan ecological conditions.•Gas chromatography coupled with mass spectrometry analyses the compounds of essential oil of Jatropha ...curcas L.•Antioxidant, antimicrobial activities of essential oil of Jatropha curcas were evaluated.
Jatropha curcas L. is a perennial energy crop in the Euphorbiaceae family that received much attention for its bio-oil multiple uses. This study was designed to determine the composition and antioxidant, antimicrobial activities of jatropha’s essential oil grown under Moroccan ecological conditions. The gas chromatography coupled with mass spectrometry (GC/MS) analysis revealed that the oil contains 39 compounds, with dominant the δ-cadinene (9.6%), α-epi-cadinol (7.38%), pulegone (5.95%), chrysanthenyl acetate (5.26%), α-cadinol (4.32%), thymol (4.03%). The antioxidant activity was evaluated by radical 2.2-diphenyl-1-picrylhydrazyl (DPPH) and by reducing power test. The result showed a moderate activity with the concentration providing 50% inhibition (IC50) 314 μg/mL and 298 μg/mL, respectively. The essential oil was used for antimicrobial activity against six bacteria and three yeasts. The yeasts strains were the most sensitive among the microorganisms tests, with minimum inhibitory concentration (MIC) ranging between 0.3 mg/mL and 0.6 mg/mL, followed by Gram-positive strains (0.3 mg/mL–1.2 mg/mL) and Gram-negative (0.6 mg/mL–2.4 mg/mL) apart from Pseudomonas aeruginosa which was a resistant strain to J. curcas L. essential oil. The results of this study showed that essential oil of J. curcas L. contains compounds with an antioxidant and antimicrobial power against several pathogenic strains and these properties may be employed in the management of microbial infections.
Faced with the ongoing energy transition and the escalating fragility of our natural ecosystems, ecological reclamation emerges as an imperative necessity. Investigation within this field has been in ...progress since the early 20th century. To gauge the advancements in this realm, elucidate the evolving research trends, and emphasize pertinent metrics, it is essential to perform a comprehensive overview of the subject. Undertaking this bibliometric study is necessary to clarify research’s current state of play, grasp research hotspots, showcase outstanding researchers, and predict future research trends. In this work, 40,386 articles were retrieved from the Scopus and Web of Science databases, and bibliometric analysis was carried out using the Biblioshiny R package (Version 4.0.0, K-Synth Srl, Naples, Italy), and Python (PyCharm Community Edition 2023.2.1)o understand the progress in this research field from 1980 to 2023. The findings reveal a consistent upward trend in the publication rate within the field of mine closure and ecological reclamation over this timeframe, culminating in 6705 articles by 2022. Notably, authors and institutions from China have taken the lead, followed closely by those from the USA and Canada in terms of article publications. This prominence can be attributed to these countries’ rapid economic growth and energetic transition, which has frequently come at the expense of environmental quality, and a rise in reclamation challenges. In this sense, the circular economy has risen in force recently, which highlights the withdrawal of the old linear economy. In coming research on mine closure and ecological reclamation, multi-scale ecological reclamation research should be reinforced, and social and economic concerns should be integrated. This study pinpointed current research hotspots and forecasted potential future research areas, providing a scientific baseline for future studies in mine closure and ecological reclamation.
The aim of this study was to assess the phytoremediation potential of fiber flax (Linum usitatissimatum L., var. Calista) cultivated in a soil contaminated with multiple metals, under real field ...conditions. A two-year (2022 and 2023) field experiment was conducted in a site contaminated with elevated concentrations of Cd, Ni, Cu, Pb, and Zn due to mining and metallurgical activities. Three different nitrogen fertilization levels were tested (N0: 0 kg N ha−1, N1: 30 kg N ha−1, N2: 60 kg N ha−1), and both spring and winter sowings were conducted. At full maturity, growth parameters and yields were measured. The phytoremediation potential of flax was assessed in terms of the metal concentrations in the above-ground biomass and of the metal uptake (i.e., the potential removal of the soil metals in g ha−1 and per year). Flax demonstrated a shorter growth cycle, with shorter and thicker plants and higher yields when sown in spring compared to winter sowing. Plant growth and productivity were not evidently influenced by additional nitrogen fertilization during plant growth. The cadmium bioaccumulation factor was 1.06, indicating that flax accumulates this metal. For Ni, Cu, Pb, and Zn, the corresponding values were 0.0, 0.04, 0.004, and 0.02, suggesting that this crop excludes these metals. The order of the higher uptake in plant tissues was as follows: Zn > Pb > Cd > Cu > Ni. In conclusion, flax demonstrated tolerance to heavy metals in the soil, effectively supporting soil restoration through cultivation. Additionally, flax showed potential as a cadmium accumulator while excluding nickel, copper, lead, and zinc.
Switchgrass (Panicum virgatum L.) has been identified in the USA as an ideal biomass crop, in relation to its wide environmental suitability, mainly linked to the availability of both upland and ...lowland ecotypes, allowing the possibility of growing this species in most of the North American region. Switchgrass is conventionally grown for forage, but more recently, it has been considered as a model biofuel crop. Early European studies on switchgrass as a bioenergy crop started in the late 1990s, when a multi-location field trial was established in Greece (Aliartos) and Italy (Ozzano) to compare the productivity of 13 switchgrass genotypes, including upland (Carthage, Blackwell, Caddo, CIR, Forestburg, SU 94-1, Summer) and lowland (Alamo, Kanlow, Pangburn, SL 93-2, SL 93-3, SL94-1) genotypes. The scope was to identify the most suitable ecotype within each environment and, possibly, the best performing variety. The trials lasted 17 years (1998–2014) in Greece and 13 years (1998–2010) in Italy. While in Italy the trial was rainfed and unfertilized, in Greece, where the soil was marginal, drip irrigation was always applied, and the plots were fertilized regularly. The biomass yields in Greece, as averages across the 17 years, were similar for the lowland and upland varieties (11.5 vs. 11.1 Mg ha−1, respectively), while in Italy, as averages across the 13 years, the differences were relevant: 15.4 vs. 11.3 Mg ha−1 for lowland and upland, respectively. Alamo (lowland) was the most productive variety, both in Greece and Italy, with average annual yields of 12.7 and 16.6 Mg ha−1, respectively; CIR in Greece (10.1 Mg ha−1) and Forestburg in Italy (9.1 Mg ha−1) (both upland) were the least productive genotypes. The present results demonstrate the good suitability of switchgrass as biomass crop for the Mediterranean climate. Despite the very marginal soil (i.e., very shallow and with a sandy texture) in the Greek trial, the application of regular fertilization and irrigation produced biomass yields above 11 Mg ha−1 (grand mean) in the present 17-year-long study.
PDF
