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Frédéric Rees

Bio: Frédéric Rees is an academic researcher from University of Lorraine. The author has contributed to research in topics: Biochar & Soil water. The author has an hindex of 11, co-authored 18 publications receiving 569 citations. Previous affiliations of Frédéric Rees include Institut national de la recherche agronomique & Université Paris-Saclay.

Papers
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TL;DR: In this paper, the effects of biochar on the mobility of metals in soils are investigated, focusing on a possible kinetic limitation by transport in biochar particles, the evolution of the biochar mineral phases, and the effect of bio char on soil pH.
Abstract: Summary Biochar, the solid product of biomass pyrolysis, can be used as a soil amendment to stabilize metals in contaminated soils. The effects of biochar on the mobility of metals in soils are, however, poorly understood. To identify the predominant processes, we focused on (i) a possible kinetic limitation by transport in biochar particles, (ii) the evolution of biochar mineral phases and (iii) the effect of biochar on soil pH. Batch experiments were conducted to measure the sorption kinetics of copper (Cu), cadmium (Cd) and nickel (Ni) and the sorption-desorption isotherms for lead (Pb), Cu, Cd, zinc (Zn) and Ni in a wood-derived biochar. Sorption data were then compared with extraction test results using biochar with one acidic and one basic soil contaminated by Zn, Cd and Pb. Kinetic results showed that biochar particle sizes controlled metal sorption rate despite a similar specific surface area, which indicated a limitation by intra-particle diffusion. Isotherms showed a partially reversible sorption to biochar following the order Pb > Cu > Cd ≥ Zn > Ni, which we explained primarily by the (co)precipitation of metals or their adsorption on specific biochar mineral phases. Effective metal immobilization was observed with biochar in both contaminated soils but could not be predicted from the sorption isotherms. This immobilization appeared to be governed by the soil pH increase, which induced a greater retention of metals on soil particles. Short-term effects of biochar on contaminated soils may therefore be controlled by diffusion in biochar particles and by soil alkalinization processes.

242 citations

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TL;DR: In this article, the effects of biochar amendments on metal uptake by two contrasted plants grown on metal-contaminated soils were investigated, including a non-hyper-accumulating plant (Lolium perenne) and a Cd-and Zn-hyperaccumulator (Noccea caerulescens).
Abstract: Biochar could be used as a soil amendment in metal contaminated soils, for safe crop production or soil remediation purposes This work was conducted to study the effects of biochar amendments on metal uptake by two contrasted plants grown on metal-contaminated soils A non-hyperaccumulating plant (Lolium perenne) and a Cd- and Zn-hyperaccumulator (Noccea caerulescens) were grown in pots on acidic (A) and alkaline (B) soil contaminated by Cd, Pb and Zn, both amended by a wood-derived biochar Biochar amendments decreased the availability of metals by increasing soil pH, but also decreased Ca, P and N availability Growth of L perenne was increased and shoot metal uptake decreased by biochar addition in both soils, although increasing biochar dose above 05 % resulted in a progressive decrease of shoot production on soil B Growth of N caerulescens was not significantly affected by biochar But an increase of Cd uptake with 5 % biochar was recorded on both soils, and of Zn uptake on soil B Beside immobilizing metals, biochar may decrease the availability of nutrients, leading either to plant deficiency or to a decreased competition with cations for metal uptake, thus enhancing extraction of metals by hyperaccumulators

96 citations

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TL;DR: An interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical-chemical parameters with their preferential methods provides recommendations to improve and harmonize specific methods for biochar analysis in the future.
Abstract: Biochar produced by pyrolysis of organic residues is increasingly used for soil amendment and many other applications. However, analytical methods for its physical and chemical characterization are yet far from being specifically adapted, optimized, and standardized. Therefore, COST Action TD1107 conducted an interlaboratory comparison in which 22 laboratories from 12 countries analyzed three different types of biochar for 38 physical-chemical parameters (macro- and microelements, heavy metals, polycyclic aromatic hydrocarbons, pH, electrical conductivity, and specific surface area) with their preferential methods. The data were evaluated in detail using professional interlaboratory testing software. Whereas intralaboratory repeatability was generally good or at least acceptable, interlaboratory reproducibility was mostly not (20% < mean reproducibility standard deviation < 460%). This paper contributes to better comparability of biochar data published already and provides recommendations to improve and harmonize specific methods for biochar analysis in the future.

88 citations

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TL;DR: Biochar can have antagonist effects on plant metal uptake by decreasing metal availability, on one hand, and by increasing root surface and inducing root proliferation, on the other hand.

75 citations

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TL;DR: In this article, the current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored, and the highest future research priorities regarding biochar's effects in soils were: functional redundancy within soil microbial communities, bioavailability of bio-char's contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity.
Abstract: Key priorities in biochar research for future guidance of sustainable policy development have been identified by expert assessment within the COST Action TD1107. The current level of scientific understanding (LOSU) regarding the consequences of biochar application to soil were explored. Five broad thematic areas of biochar research were addressed: soil biodiversity and ecotoxicology, soil organic matter and greenhouse gas (GHG) emissions, soil physical properties, nutrient cycles and crop production, and soil remediation. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity. Methodological and other constraints to achieve the required LOSU are discussed and options for efficient progress of biochar research and sustainable application to soil are presented.

54 citations


Cited by
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TL;DR: Results of redundancy analysis indicated biochar could shift the soil microbial community by changing soil chemical properties, which modulate N-cycling processes and soil N2O emissions.
Abstract: Biochar has been suggested to improve acidic soils and to mitigate greenhouse gas emissions. However, little has been done on the role of biochar in ameliorating acidified soils induced by overuse of nitrogen fertilizers. In this study, we designed a pot trial with an acidic soil (pH 4.48) in a greenhouse to study the interconnections between microbial community, soil chemical property changes, and N2O emissions after biochar application. The results showed that biochar increased plant growth, soil pH, total carbon, total nitrogen, C/N ratio, and soil cation exchange capacity. The results of high-throughput sequencing showed that biochar application increased α-diversity significantly and changed the relative abundances of some microbes that are related with carbon and nitrogen cycling at the family level. Biochar amendment stimulated both nitrification and denitrification processes, while reducing N2O emissions overall. Results of redundancy analysis indicated biochar could shift the soil microbial community by changing soil chemical properties, which modulate N-cycling processes and soil N2O emissions. The significantly increased nosZ transcription suggests that biochar decreased soil N2O emissions by enhancing its further reduction to N2.

373 citations

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TL;DR: Recent progresses in understanding metal-biochar interactions in soils, potential risks associated with biochar amendment, and application of biochar in soil remediation in China indicate that the remediation effect depends on the characteristics of both biochar and soil and their interactions.

362 citations

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TL;DR: This review highlights the potential for improving plant resistance to TE(s) stress by BC application and provides a theoretical basis for application of BC in TE (s) contaminated soils worldwide.
Abstract: Trace elements (TEs) contamination is one of the main abiotic stresses which limit plant growth and deteriorate the food quality by their entry into food chain. In recent, biochar (BC) soil amendment has been widely reported for the reduction of TE(s) uptake and toxicity in plants. This review summarizes the role of BC in enhancing TE(s) tolerance in plants. Under TE(s) stress, BC application increased plant growth, biomass, photosynthetic pigments, grain yield, and quality. The key mechanisms evoked are immobilization of TE(s) in the soil, increase in soil pH, alteration of TE(s) redox state in the soil, and improvement in soil physical and biological properties under TE(s) stress. However, these mechanisms vary with plant species, genotypes, growth conditions, duration of stress imposed, BC type, and preparation methods. This review highlights the potential for improving plant resistance to TE(s) stress by BC application and provides a theoretical basis for application of BC in TE(s) contaminated soils worldwide.

349 citations

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TL;DR: This work identifies a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resolution spectro(micro)scopy and mass spectrometry, which strengthens biochar-water interactions and thus enhances nutrient retention.
Abstract: Amending soil with biochar (pyrolized biomass) is suggested as a globally applicable approach to address climate change and soil degradation by carbon sequestration, reducing soil-borne greenhouse-gas emissions and increasing soil nutrient retention. Biochar was shown to promote plant growth, especially when combined with nutrient-rich organic matter, e.g., co-composted biochar. Plant growth promotion was explained by slow release of nutrients, although a mechanistic understanding of nutrient storage in biochar is missing. Here we identify a complex, nutrient-rich organic coating on co-composted biochar that covers the outer and inner (pore) surfaces of biochar particles using high-resolution spectro(micro)scopy and mass spectrometry. Fast field cycling nuclear magnetic resonance, electrochemical analysis and gas adsorption demonstrated that this coating adds hydrophilicity, redox-active moieties, and additional mesoporosity, which strengthens biochar-water interactions and thus enhances nutrient retention. This implies that the functioning of biochar in soil is determined by the formation of an organic coating, rather than biochar surface oxidation, as previously suggested. Biochar promotes plant growth via a slow release of nutrients; however, a mechanistic understanding of nutrient storage in biochar is lacking. Here, using high-resolution spectromicroscopy and mass spectrometry, the authors identify an organic coating on co-composted particles that enhances nutrient retention.

332 citations