Remediation of Contaminated Soil for Food Security

A special issue of Agronomy (ISSN 2073-4395). This special issue belongs to the section "Soil and Plant Nutrition".

Deadline for manuscript submissions: closed (20 September 2020) | Viewed by 50341

Special Issue Editors


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Guest Editor
Departmento de Química Agrícola y Bromatología, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain
Interests: soil biogeochemistry, plant nutrition, soil contamination, waste recycling

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Guest Editor
The James Hutton Institute, Craigiebuckler, Aberdeen AB15 8QH, UK
Interests: soil contamination; waste recycling; technosoils; urban soils

Special Issue Information

Dear Colleagues,

Soil is a non-renewable resource critical for ecosystem functioning. Inorganic and organic contaminants degrade soils, disturb the ecosystem balance, and pose a risk to human health. The extent of contaminated soils worldwide is vast, whilst the expansion of populations increasingly results in the loss of fertile functional agricultural soils through soil sealing. This combination will result in the necessity to utilize degraded and contaminated soils for food production in the future and formulate innovative solutions to grow food safely in a range of challenging situations. In this Special Issue, the role of in-situ soil remediation practices will be presented with a special emphasis on food security. Inter-disciplinary solutions to the challenge of soil contamination will be reviewed to provide relevant and timely information to a range of stakeholders concerned with the maintenance and enhancement of environmental protection and food security in the presence of contaminated soils.

Dr. Eduardo Moreno-Jiménez
Dr. Luke Beesley
Guest Editors

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Keywords

  • soil pollution
  • urban soils
  • remediation
  • amendments
  • heavy metals
  • PAHs
  • microplastics

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Published Papers (11 papers)

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Research

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16 pages, 1037 KiB  
Article
Phytoextraction with Maize of Soil Contaminated with Copper after Application of Mineral and Organic Amendments
by Mirosław Wyszkowski and Marzena S. Brodowska
Agronomy 2020, 10(10), 1597; https://doi.org/10.3390/agronomy10101597 - 18 Oct 2020
Cited by 11 | Viewed by 2638
Abstract
This study aimed to determine the possibility to increase the the effect of different amendments (compost, bentonite and zeolite) on the shoot yield and the concentration of trace elements in shoots of maize (Zea mays L.) on soil contaminated with Cu. The [...] Read more.
This study aimed to determine the possibility to increase the the effect of different amendments (compost, bentonite and zeolite) on the shoot yield and the concentration of trace elements in shoots of maize (Zea mays L.) on soil contaminated with Cu. The yield of shoots and concentration of the trace elements in shoots of maize depended on Cu dose and amendment incorporation into the sandy soil. Cu-spiked soil caused an increase the yield of shoots (only to 100 mg Cu/kg of soil), in the concentration of Cu, Co, Mn, Ni and Fe in shoots of maize and, to a smaller degree, in the concentration of Zn and bioconcentration factor (BCF) of all elements except copper, compared to the control soil without Cu. Under the influence of 150 and 200 mg Cu per kg of soil, a decrease in yield of shoots of maize was observed. Compost, bentonite and zeolite increased the yield of shoots and reduced the concentration of Cu, Co, Mn, Fe and Zn in shoots of maize. Bentonite had a more positive effect than compost and zeolite on the yield of shoots and the concentration of Co, Mn and Zn in shoots of maize. The effect of these amendments on the Cu and Fe concentration in shoots of maize was reverse. A reverse effect of these amendments (especially bentonite and zeolite) on the Ni concentration in plants was observed. The amendments applied to soil, especially compost, increased the BCF of Ni and, to a small degree, BCF of Cu in shoots of maize, compared to the control series. Compost, zeolite and especially bentonite are very good amendments in the restoration of maize growth in polluted areas. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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16 pages, 2925 KiB  
Article
Optimising Sample Preparation and Calibrations in EDXRF for Quantitative Soil Analysis
by Maame E. T. Croffie, Paul N. Williams, Owen Fenton, Anna Fenelon, Konrad Metzger and Karen Daly
Agronomy 2020, 10(9), 1309; https://doi.org/10.3390/agronomy10091309 - 2 Sep 2020
Cited by 20 | Viewed by 5528
Abstract
Energy-dispersive X-ray fluorescence spectrometry (EDXRF) is a rapid and inexpensive method for soil analysis; however, analytical results are influenced by particle size effects and spectral interferences. The objective of this study was to optimise sample preparation and calibrations to improve the accuracy of [...] Read more.
Energy-dispersive X-ray fluorescence spectrometry (EDXRF) is a rapid and inexpensive method for soil analysis; however, analytical results are influenced by particle size effects and spectral interferences. The objective of this study was to optimise sample preparation and calibrations to improve the accuracy of EDXRF for soil tests. Methods of sample preparation were compared by calculating the recoveries of 13 elements in four International Soil-Analytical Exchange (ISE) standards prepared as loose powder (LP), pressed pellet (PP), and pressed pellet with wax binder (PPB). A matching library (ML) was created and evaluated against the fundamental parameters (FP) calibration using 20 ISE standards. Additionally, EDXRF results of 41 tillage soils were compared with Inductively coupled plasma optical emission spectrometry (ICP-OES) results. The PPB had most recoveries within the acceptable range of 80–120%; conversely, PP yielded the poorest element recoveries. For the calibration, the ML provided better recoveries of Ni, Pb, Cu, Mg, S, P, and Cr; however, for Zn, and Mn, it had the opposite effect. Furthermore, EDXRF results compared with ICP-OES separated by soil texture class for Al, K, Mn, and Fe. In conclusion, the EDXRF is suitable for quantifying both trace elements and macronutrients in contaminated soils and has the potential to provide screening or prediction of soil texture in agriculture. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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17 pages, 1390 KiB  
Article
Effects of Different In Situ Remediation Strategies for an As-Polluted Soil on Human Health Risk, Soil Properties, and Vegetation
by Diego Baragaño, José Luis R. Gallego, Gaspar Baleriola and Rubén Forján
Agronomy 2020, 10(6), 759; https://doi.org/10.3390/agronomy10060759 - 26 May 2020
Cited by 13 | Viewed by 2995
Abstract
The demand for soils for recreational uses, gardening, or others in urban and periurban areas is increasing, and thus the presence of polluted technosols in these areas requires nature-based in situ remediation technologies. In this context, the capacity of three amendments, namely zero [...] Read more.
The demand for soils for recreational uses, gardening, or others in urban and periurban areas is increasing, and thus the presence of polluted technosols in these areas requires nature-based in situ remediation technologies. In this context, the capacity of three amendments, namely zero valent iron nanoparticles (nZVI), compost and a mixture of compost and biochar, to immobilise As in a polluted technosol simultaneously cultivated with Lolium perenne L. were tested and compared. The characteristics of the soil were comprehensively characterised by chemical and X-ray analysis to determine As contents, distribution, and mineralogy. As mobility was evaluated by the RBA methodology and then potential human health risks, both carcinogenic and non-carcinogenic, were assessed in all treatments. The nZVI treatment reduced risks due to the As immobilisation obtained (41% As decrease, RBA test), whereas the organic amendments did not imply any significant reduction of the RBA values. As to soil properties, the organic treatments applied lowered the pH values, increasing cation exchange capacity, and carbon and nutrient contents. To determine impacts over plant production, fresh biomass, As, Ca, Fe, K, Mg, Na and P were measured in Lolium under the different treatments. Notably, organic amendments improved As extraction by plants (57% increase), as well as fresh biomass (56% increase). On the contrary, nZVI diminished As extraction (65% decrease) and promoted a fresh biomass decrease of 57% due to nutrients immobilisation (61% decrease of P in plants tissues). Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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16 pages, 1716 KiB  
Article
Ecosystem (Dis)benefits Arising from Formal and Informal Land-Use in Manchester (UK); a Case Study of Urban Soil Characteristics Associated with Local Green Space Management
by Matthew Dennis, Luke Beesley, Michael Hardman and Philip James
Agronomy 2020, 10(4), 552; https://doi.org/10.3390/agronomy10040552 - 10 Apr 2020
Cited by 8 | Viewed by 3931
Abstract
Urban soils are subject to anthropogenic influences and, reciprocally, provide benefits and disbenefits to human wellbeing; for example carbon storage, nutrient cycling and the regulation trace element and contaminant mobility. Collective stewardship of urban green commons provides contemporary examples of the diversity of [...] Read more.
Urban soils are subject to anthropogenic influences and, reciprocally, provide benefits and disbenefits to human wellbeing; for example carbon storage, nutrient cycling and the regulation trace element and contaminant mobility. Collective stewardship of urban green commons provides contemporary examples of the diversity of uses and management of green space in cities and represents a growing movement in user participation in, and awareness of, the importance of urban ecological health. Exploring the range of social-ecological benefits exemplified in the urban environment has generally focused on above-ground processes, with few studies examining the potential for (dis)benefits arising from edaphic characteristics of collectively-managed spaces. An investigation into the influence of formal and informal green space management on carbon fluxes and heavy metal concentrations in urban soils was carried out in Manchester (UK) finding that carbon storage in soils of collectively managed urban green commons (7.15 ± 1.42 kg C m−2) was significantly greater than at formally managed sites (for example city parks: 5.08 ± 0.69 kg C m−2), though the latter exhibited reduced losses through CO2 emission. Variation in heavy metal concentrations and mobility were likewise observed, exemplified by the acidification of surface soils by leaf litter at orchard sites, and the resultant increase in the mobility of lead (Pb) and zinc (Zn). The results of this study indicate the importance of small-scale contemporary urban green space management on selected ecosystem services provided by the limited soil resource of cities. Thus, a greater consideration of the effects of horticultural and amenity activities with regards to soil quality/functionality is required to ensure available urban green commons retain or increase their ecological quality over time. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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19 pages, 2737 KiB  
Article
Effective Amendments on Cadmium, Arsenic, Chromium and Lead Contaminated Paddy Soil for Rice Safety
by Aman Ullah, Yibing Ma, Jumei Li, Nazia Tahir and Babar Hussain
Agronomy 2020, 10(3), 359; https://doi.org/10.3390/agronomy10030359 - 5 Mar 2020
Cited by 33 | Viewed by 4955
Abstract
Contamination of paddy soils with heavy metals and metalloids poses a risk to human health through the food chain. For safe agricultural production in contaminated paddy soils, “in situ” remediation through the unavailability of heavy metals from contaminated soils was investigated in order [...] Read more.
Contamination of paddy soils with heavy metals and metalloids poses a risk to human health through the food chain. For safe agricultural production in contaminated paddy soils, “in situ” remediation through the unavailability of heavy metals from contaminated soils was investigated in order to develop cost-effective and eco-friendly approaches for soils contaminated with complexed heavy metals (HMs) and metalloids. In the present study, the effectiveness of different soil amendments, including sulfur-containing materials (hair or cysteine), manganese compounds as an antagonist and an oxidant, zeolite and iron oxide as adsorbents, and their combinations through coating or modification, was investigated by a pot experiment with rice plants and chemical analysis. Two levels of each treatment were made, termed X1 and X2, which were a single and double dose of each treatment respectively, while CaCO3 was used as a basal and pH enhancement amendment in all treatments to identify the best combination of the above treatments in the in situ remediation of heavy metals and metalloids. The rice plants were kept under the flooded condition. Results indicated that the bioavailability of As, Cd, Cr, and Pb in soil was significantly decreased with level two (X2) of iron oxide coated with modified hairs (T7X2) followed by level two (X2) of zeolite coated with KMnO4. The iron oxide coated with modified hairs (X2) decreased the concentrations of heavy metals and metalloids in rice plants in the order Pb ˃ As ˃ Cr ˃ Cd by 81%, 80%, 79% and 46%, respectively, followed by zeolite coated with KMnO4 (X2) in the order Pb ˃ As ˃ Cr ˃ Cd by 78%, 76%, 71%, and 31%, respectively, to control. The available content of these elements in soil was decreased in the order As > Cr> Pb > Cd by 67%, 66%, 64% and 60%, respectively, through iron oxide coated with modified hairs, followed by zeolite coated with KMnO4 in the order Pb ˃ Cr ˃ Cd ˃ As by 57%, 53%, 50%, and 46%, respectively, to control, which can explain the decreased bioavailability by these amendments. In addition, the maximum shoot dry and leaf area were noticed in the pots treated with iron oxide coated with modified hairs and zeolite coated with KMnO4. There is potential to use modified hairs (MHs) with iron oxide and KMnO4-coated zeolite as soil amendments to develop a cost-effective and efficient “in situ” remediation technology for As, Cd, Pb, and Cr-contaminated rice paddy soils, especially for the soils with complex contamination by Cd and As. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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9 pages, 1325 KiB  
Article
Carbon and Metal(loid)s in Parkland and Road Verge Surface Soils in the City of Liverpool, UK
by Luke Beesley, Eduardo Moreno-Jiménez, Phil Jenn and Nicholas W. Lepp
Agronomy 2020, 10(3), 335; https://doi.org/10.3390/agronomy10030335 - 2 Mar 2020
Cited by 2 | Viewed by 2529
Abstract
Urban soils are at the interface between land and people and provide a wide variety of important ecosystem services to highly populous areas. The aims of this soil survey were (1) to measure the bulk density, carbon (C) storage and pH of surface [...] Read more.
Urban soils are at the interface between land and people and provide a wide variety of important ecosystem services to highly populous areas. The aims of this soil survey were (1) to measure the bulk density, carbon (C) storage and pH of surface soils (0–15 cm depth) from public spaces (parks and road verges) in the city of Liverpool, UK, and (2) to determine the likely impact of these master variables on heavy metal concentrations (As, Cd, Cu, Pb and Zn). The bulk densities and organic matter contents varied considerably in the predominantly sandy textured soils within the city boundary, resulting in diverse C densities from 1–10 kg C m2. Organic carbon formed the majority of the labile, water-soluble and extractable C pool in these soils, a fact not easily elucidated from their organic matter or C content alone. The copper and lead concentrations in the sampled soils were correlated with organic matter and organic carbon in water-extracts. Cadmium and zinc appeared to be dependent only on soil pH, whilst arsenic was related positively to organic matter, but negatively to pH. Interrelationships, and hence synonymous distributions, of all metal(loid)s existed, but were strongest between Cu and As, and Cu and Pb. These results suggest that the diverse bulk densities, and hence carbon storage, of the urban soils surveyed influenced the dispersal of metals and arsenic. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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14 pages, 1053 KiB  
Article
Performance of Medicago sativa Grown in Clay Soil Favored by Compost or Farmyard Manure to Mitigate Salt Stress
by Sonia Mbarki, Milan Skalicky, Ons Talbi, Amrita Chakraborty, Frantisek Hnilicka, Vaclav Hejnak, Marek Zivcak, Marian Brestic, Artemi Cerda and Chedly Abdelly
Agronomy 2020, 10(1), 94; https://doi.org/10.3390/agronomy10010094 - 9 Jan 2020
Cited by 23 | Viewed by 5120
Abstract
The use of saline water for the irrigation of forage crops to alleviate water scarcity has become necessary in semi-arid and arid regions and researchers have been seeking ways to offset the harmful results of soil salinity. Soil amendments with compost, manure and [...] Read more.
The use of saline water for the irrigation of forage crops to alleviate water scarcity has become necessary in semi-arid and arid regions and researchers have been seeking ways to offset the harmful results of soil salinity. Soil amendments with compost, manure and other organic material provide a valuable source of plant nutrients and appear to speed up soil recovery. The aim of this study was to compare the benefits of farmyard manure and a municipal solid waste (MSW) compost (40 mg ha−1) for raising alfalfa (Medicago sativa, cv. Gabès) under salt-water irrigation. Both compost and manure improved plant mineral uptake and growth of alfalfa cultivated in clay soil. Using compost in clay soil increased the content of copper (Cu), cadmium (Cd), and zinc (Zn) in plant tissues compared to manure, while the bio-accumulation factor (BAF) of Cu, Pb and Zn was higher in plants grown with manure compared to MSW compost with salt stress. Compost addition could enhance alfalfa growth under salt stress, which depends on salt doses and can greatly improve the recovery effects in a cost-effective way, although additional amendment type should receive special attention in order to be used as a tool for sustainable agriculture. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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15 pages, 1745 KiB  
Article
Agro-Environmental Benefit and Risk of Manure- and Bone Meal-Derived Pyrogenic Carbonaceous Materials as Soil Amendments: Availability of PAHs, PTEs, and P
by Vladimír Frišták, Martin Pipíška, Gerhard Soja, Alena Klokočíková Packová, Michal Hubeňák and Magdaléna Kadlečíková
Agronomy 2019, 9(12), 802; https://doi.org/10.3390/agronomy9120802 - 24 Nov 2019
Cited by 5 | Viewed by 3251
Abstract
The worldwide boom of biochar and pyrogenic carbonaceous material application as a potential soil additive has brought about not only agricultural benefits such as enhanced crop yield, nutrients supply (P), and soil organic carbon increase, but also, on the other hand, environmental risk [...] Read more.
The worldwide boom of biochar and pyrogenic carbonaceous material application as a potential soil additive has brought about not only agricultural benefits such as enhanced crop yield, nutrients supply (P), and soil organic carbon increase, but also, on the other hand, environmental risk of organic (polycyclic aromatic hydrocarbons (PAHs)) and potentially toxic element (PTE) penetration into arable soils. Therefore, our study assessed pyrogenic carbonaceous materials (PCM) produced from the P-rich feedstocks—chicken manure (CM) and bone meal (BM)—as promising and safe alternatives for inorganic P fertilizers. Pyrogenic materials produced in the process of slow pyrolysis at residence time 2 h, 400 and 500 °C, were characterized by determination of pH, electrical conductivity (EC), elemental analysis of total C, H, N, S scanning electron microscopy (SEM), total content of P, selected potentially toxic elements (PTEs), and available forms of PTEs and P by diethylenetriaminepentaacetic acid (DTPA) and calcium-acetate-lactate (CAL) extractions. CMPCM4, CMPCM5, BMPCM4, and BMPCM5 were characterized by determination of total 16 US-EPA (U.S. Environmental Protection Agency) PAHs by toluene extraction protocol and available concentrations by Tenax resin approach. Additionally, CMPCM4, CMPCM4, BMPCM4, and BMPCM5 were tested in earthworm avoidance test with Eisenia foetita and short-term rye-seedling germination test. Obtained results showed decreasing of total carbon in the order of BM > BMPCM4 > BMPCM5 and increasing in the order of CM < CMPCM4 < CMPCM5. Total phosphorus content increased from 56.8 ± 1.7 g kg−1 (BM) to 85.2 ± 4.2 g kg−1 (BMPCM4) to 110.5 ± 7.0 g kg−1 (BMPCM5). In the case of chicken manure-derived pyrogenic materials, total phosphorus content increased in the order of CM (22.9 ± 2.0 g kg−1) < CMPCM4 (37.0 ± 4.5 g kg−1) < CMPCM5 (40.0 ± 3.4 g kg−1). Availability of selected PTEs and P decreased in pyrogenic materials compared to feedstock. Total concentration of ∑16-US-EPA PAHs in BMPCM4 and BMPCM5 was 3.92 mg kg−1; CMPCM4, 7.33 mg kg−1; and CMPCM, 6.69 mg kg−1. The Tenax-available ∑16-PAHs showed concentrations of 0.53 mg kg−1 for BMPCM4, 0.26 mg kg−1 for BMPCM5, 1.13 mg kg−1 for CMPCM4, and 0.35 mg kg−1 for CMPCM5. Total P concentrations determined in rye aboveground tissues showed the highest accumulation ability in the case of CMPCM5 compared to other samples. Pyrogenic carbonaceous materials produced from chicken manure and bone meal at 400 and 500 °C have the potential to be P slow release fertilizers and may be ecologically safe. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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17 pages, 2379 KiB  
Article
Evaluation of Commercial Humic Substances and Other Organic Amendments for the Immobilization of Copper Through 13C CPMAS NMR, FT-IR, and DSC Analyses
by Begoña Mayans, Javier Pérez-Esteban, Consuelo Escolástico, Enrique Eymar and Alberto Masaguer
Agronomy 2019, 9(11), 762; https://doi.org/10.3390/agronomy9110762 - 16 Nov 2019
Cited by 23 | Viewed by 3734
Abstract
The application of organic amendments to contaminated agricultural lands can immobilize metals and improve soil conditions. The chemical structures and long-term stability of commercial humic substances and other composted organic amendments (sheep and horse manure, vermicompost, pine bark, and pruning waste) were analyzed [...] Read more.
The application of organic amendments to contaminated agricultural lands can immobilize metals and improve soil conditions. The chemical structures and long-term stability of commercial humic substances and other composted organic amendments (sheep and horse manure, vermicompost, pine bark, and pruning waste) were analyzed using 13C CPMAS NMR, FT-IR, and DSC to evaluate their use in soil remediation. The interactions of humic substances and manure with Cu (0 and 5000 mg kg−1) at different pH (2.5 and 5.0) were studied through a batch adsorption experiment observing the changes in their molecular structure using spectroscopic techniques. Humic substances exhibited high aromaticity and phenolic and carboxylic group content, with great affinity for Cu complexation. Humic substances and pruning waste were the most stable due to their high recalcitrant organic matter contents, whereas manure was the least stable, given the labile nature of its organic matter content. There were considerable changes in the carboxylic and phenolic groups of humic substances with pH, and also with Cu, albeit in a lesser extent, especially at pH 5.0, suggesting the great sorption capacity of humic substances and the key role of pH and these functional groups in metal complexation. Manure did not exhibit such changes. Commercial humic substances could be useful amendments for the remediation of contaminated agricultural soils due to their high sorption capacities and long-term stability. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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18 pages, 1215 KiB  
Article
Influence of Pyrolyzed Grape-Seeds/Sewage Sludge Blends on the Availability of P, Fe, Cu, As and Cd to Maize
by Sara Aceña-Heras, Jeff Novak, María Luz Cayuela, Jesus M. Peñalosa and Eduardo Moreno-Jiménez
Agronomy 2019, 9(7), 406; https://doi.org/10.3390/agronomy9070406 - 22 Jul 2019
Cited by 7 | Viewed by 3675
Abstract
Current intensive agricultural practices, although highly successful in terms of production, have been found to be environmentally unsustainable. One of the crucial approaches to increase agricultural sustainability is the recycling of organic wastes, since these materials often contain many beneficial nutrients for soil [...] Read more.
Current intensive agricultural practices, although highly successful in terms of production, have been found to be environmentally unsustainable. One of the crucial approaches to increase agricultural sustainability is the recycling of organic wastes, since these materials often contain many beneficial nutrients for soil and agriculture. Recently, pyrolytic conversion of biodegradable waste into charred material has gained global attention as an amendment to recycle nutrients while improving soil health. Increasing interest in the beneficial applications of pyrolyzed biomass has expanded multidisciplinary areas for science and engineering. The fertilizers used in this study were prepared by pyrolyzing mixtures of two abundant residues in Mediterranean areas: grape seeds and sewage sludge, in different proportions (100% GS, 75% GS-25% SS, 50% GS-50% SS, 25% GS-75% SS, 100% SS). In addition, fresh sludge was mixed with pyrolyzed grape seeds and included as an additional treatment. In this study, the positives and negatives of the application of biochars on agronomic potential and environmental risk have been addressed, taking into account P, Zn, Cu, Fe, As and Cd. In order to choose the best mixture, it is necessary to find a compromise between maximizing the beneficial elements that are translocated to the plant crop, as well as reducing the elements that are leached. Results of a 6-week greenhouse study indicated that the unpyrolyzed sludge mixture contained the largest amount of available nutrients Fe, Cu and P. In agreement, this treatment mixed with a Chromic Luvisol soil (40 ton/ha) increased the uptake of these elements in corn (Zea mays L.—LG ambitious). The yield also increased by 60% in this treatment. However, this mixture also contained more contaminants (As, Cd) which were extracted with Ammonium Bicarbonate-DTPA. According to our results, the treatments where grape seeds and sewage sludge were mixed at 50% and then pyrolyzed exhibited the optimal compromise between efficiency (nutrients uptake) and tolerable levels of potentially toxic elements in leachates. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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Review

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22 pages, 1896 KiB  
Review
Arbuscular Mycorrhizal Fungi as Potential Agents in Ameliorating Heavy Metal Stress in Plants
by Rajni Dhalaria, Dinesh Kumar, Harsh Kumar, Eugenie Nepovimova, Kamil Kuča, Muhammad Torequl Islam and Rachna Verma
Agronomy 2020, 10(6), 815; https://doi.org/10.3390/agronomy10060815 - 9 Jun 2020
Cited by 139 | Viewed by 11011
Abstract
Heavy metal accumulation in plants is a severe environmental problem, rising at an expeditious rate. Heavy metals such as cadmium, arsenic, mercury and lead are known environmental pollutants that exert noxious effects on the morpho-physiological and biological attributes of a plant. Due to [...] Read more.
Heavy metal accumulation in plants is a severe environmental problem, rising at an expeditious rate. Heavy metals such as cadmium, arsenic, mercury and lead are known environmental pollutants that exert noxious effects on the morpho-physiological and biological attributes of a plant. Due to their mobile nature, they have become an extended part of the food chain and affect human health. Arbuscular mycorrhizal fungi ameliorate metal toxicity as they intensify the plant’s ability to tolerate metal stress. Mycorrhizal fungi have vesicles, which are analogous to fungal vacuoles and accumulate massive amount of heavy metals in them. With the help of a pervasive hyphal network, arbuscular mycorrhizal fungi help in the uptake of water and nutrients, thereby abating the use of chemical fertilizers on the plants. They also promote resistance parameters in the plants, secrete a glycoprotein named glomalin that reduces the metal uptake in plants by forming glycoprotein–metal complexes, and improve the quality of the soil. They also assist plants in phytoremediation by increasing the absorptive area, increase the antioxidant response, chelate heavy metals and stimulate genes for protein synthesis that reduce the damage caused by free radicals. The current manuscript focuses on the uptake of heavy metals, accumulation, and arbuscular mycorrhizal impact in ameliorating heavy metal stress in plants. Full article
(This article belongs to the Special Issue Remediation of Contaminated Soil for Food Security)
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