Marie-France Dignac

• French National Institute for Agriculture, Food, and Environment (INRAE)

Science shows mounting global health risks associated with plastics life cycle pollution. Leveraging evidence and streamlining research to inform policy is critical to safeguarding people and planet. We conducted an electronic survey questionnaire, between 16th April and 16th August 2024, amongst United Nations government delegates developing the G...

Salt marshes are among the most efficient blue carbon sinks worldwide. The fate of this carbon is uncertain due to limited knowledge about organic matter (OM) decomposition processes under sea-level rise. In an in-situ manipulative experiment, we compared salt marsh OM decomposition and quality across simulated sea-level scenarios (by modifying the...

La pollution des sols par les plastiques est beaucoup moins bien documentée que celle des océans, alors que les quantités de plastiques dans les sols seraient de 4 à 23 fois plus élevées en masse que dans les océans. La « pollution plastique » est devenue une menace pour l’environnement et la santé humaine. Cet article fait le point sur les sources...

This policy brief covers alternatives to conventional, durable fossil-based plastics. It addresses their potential advantages and disadvantages, limitations and risks as well as the role of the Global Plastics Treaty.

In this study, we combined Rock-Eval® analysis, analytical pyrolysis, and wet-chemical extractions, assisted by Fourier transform infrared spectroscopy (FTIR), and measurements of soil heterotrophic respiration. Our objective was to assess the biological and thermal stability of mixed-nature soil organic matter (SOM) derived from grass litter and k...

There is currently an intense debate about the potential for additional organic carbon storage in soil, the strategies by which it may be accomplished and what the actual benefits might be for agriculture and the climate. Controversy forms an essential part of the scientific process, but on the topic of soil carbon storage, it may confuse the agric...

Microplastic (MP) input into agroecosystems is of particular concern as their sources are diverse (mulching films, biosolid application, wastewater irrigation, flooding, atmospheric input, road runoff). Compost application, which is needed to sustain soil ecosystem services in the context of a circular economy, may be a source of microplastics. The...

Competition, publication, projects, funding, career: researchers are "squeezed like lemons". These pressures can erode their creativity. For the past ten years, the Organic Matter Network has been organizing research schools, with a major part devoted to original creative activities based on the sensorial, artistic or poetic perception of its resea...

Due to its influence on multiple soil processes, water intervenes in biogeochemical cycles at multiple spatial scales with contrasting effects on soil organic carbon (SOC) dynamics. On all scales, water availability influences biological processes, such as plant growth and (micro-)biological activity, leading to organic matter input, its decomposit...

In the last decade, our understanding of plant litter decomposition and soil organic matter formation substantially improved but critical blind spots remain. Particularly, the role of detritivores, i.e. soil animals that feed on litter and soil, is poorly understood and notoriously missing from biogeochemical models. This major gap results from met...

The role of earthworms on biogeochemical carbon cycling is a major knowledge gap resulting from the difficulty of isolating and exploring the effects provided by the diversity of organisms. In this study, we investigated the effect of six earthworm species belonging to three ecological categories on soil organic carbon (SOC) mineralization. To this...

Three-dimensional (3D) printing in soil science is relatively rare but offers promising directions for research. Having 3D-printed soil samples will help academics and researchers conduct experiments in a reproducible and participatory research network and gain a better understanding of the studied soil parameters. One of the most important challen...

The objective of the study was to characterise co-composting dynamics and maturity of the end products of sewage sludge/ green waste mixtures. We analysed all initial substrates and co-composts, sampled at different composting times for studying (1) physicochemical parameters and (2) organic matter biodegradation and biotransformation using pyrolys...

Microbial use efficiency is thought to greatly influence organic carbon storage in soils through the formation of decomposition products and their stabilization as organo-mineral complexes. Earthworm activity may play a significant role in these processes. Of the three ecological earthworm groups only two (endogeic and anaecic species) are thought...

Lagooning sludge (LS), which is used as soil amendment in Morocco, may contain microplastics (MPs). The aim of this study was to examine the effect of dewatering and co-composting of LS with green waste (GW) on the MPs’ evolution. In this context the present study proposes fast-preliminary steps to detect plastics in lagooning sewage sludge before...

Soils are key environmental compartments providing many products and services to humans. Because of their high variability, it is difficult to understand and compare the functions and services offered by different types of soils. 3D printing technologies have the potential to overcome these challenges by manufacturing complex, endlessly replicable,...

In a context of global change, soil has been identified as a potential carbon (C) sink, depending on land-use strategies. To detect the trends in carbon stocks after the implementation of new agricultural practices, early indicators, which can highlight changes in short timescales, are required. This study proposes the combined use of stable isotop...

The quality of organic soil amendments such as composts and vermicomposts can be improved by using additives during their production. However, little is known about the impact of these materials on carbon flow in the plant-soil system. We investigated the impact of organic amendments produced through composting and vermicomposting in the presence o...

The soil, at the interface between geosphere, biosphere, and atmosphere, is a particularly challenging object to study. The ecological and environmental impacts of soil functioning encourage soil scientists to exploit new technologies to generate new data or develop new research protocols. Among these technologies, 3D printing is a promising techno...

Abstract. In a context of global change, soil has been identified as a potential carbon (C) sink, depending on land-use strategies. To detect the trends of carbon stocks after the implementation of new agricultural practices, early indicators, which can highlight changes in short timescales are required. This study proposes the combined use of sta...

Clay-sized soil minerals are known to protect organic carbon (OC) from mineralisation by formation of organo-mineral associations limiting its availability to microorganisms. The impact of soil fauna on these processes is poorly known. The aim of this study was to investigate the effect of earthworms on organic matter (OM) decomposition and associa...

Stabilization of organic matter (OM) against decomposition and its de-stabilization leading to mineralization are important processes controlling greenhouse gas emissions and carbon sequestration in soils. Soil organisms, particularly earthworms, may greatly influence these processes through their potential impact on the interaction of OM with clay...

Land management has a strong effect on biogeochemical cycles and may strongly affect soil organic carbon storage. In the Republic of Congo, eucalyptus clones were introduced in 1978 in coastal savanna to produce pulpwood. The aim of this study was to use lignin, a biomarker of specific plant origin and stable carbon isotopes to investigate the mech...

Urban compost application in agroecosystems enhances soil fertility but can also be a source of (micro) plastics, which are not completely removed during the composting process. Knowledge of the fate of these plastics in regularly-amended soils is thus an issue for the environmental management of these soils. The aims of this study were (1) to deve...

Composting and vermicomposting are sustainable strategies to transform organic wastes into organic amendments, valuable as potting media or soil conditioner. However, the negative aspects of these processes are emissions of greenhouse gases and odorous molecules and final product potentially containing toxic compounds. These negative aspects can be...

https://doi.org/10.1016/j.jaap.2018.04.004 --------------- A novel method coupling pyrolysis with mid-infrared spectroscopy (Py-MIRS) was developed to characterize soil organic matter (SOM) chemistry in soils. The pyrolyzer was interfaced to the MIR spectrometer by means of a Brill cell™ (CDS Analytica). The set-up generates pyrolysis fingerprint...

Increased mineralization of the organic matter (OM) stored in permafrost is expected to constitute the largest additional global warming potential from terrestrial ecosystems exposed to a warmer climate. Chemical composition of permafrost OM is thought to be a key factor controlling the sensitivity of decomposition to warming. Our objective was to...

The development of bacterial biofilms in natural environments may alter important functions, such as pollutant bioremediation by modifying both the degraders' physiology and/or interactions within the matrix. The present study focuses on the influence of biofilm formation on the metabolism of a pesticide, 2,4-dichlorophenoxyacetic acid (2,4-D), by...

Scanning Electron Microscopy of the sand grains surface at 0, 1, 2, and 3 days of incubation.

Proportion of CRing in each FAME of C.necator JMP134 for the control (A) and sand (B) microcosms at each sampling date. Error bars correspond to the standard deviation calculated for 3 replicates. The gray line represents the proportion of CRing in the substrate (2,4-D) used.

Example of chromatograms (GC-FID) of the lipid fraction obtained from the sand samples at each sampling date. 2,4-D but no metabolites were detected. The other peaks corresponded to the bacterial fatty acids.

Composition (molar percentage) of C.necator JMP134 FAME profiles in the control (upper) and sand (lower) samples at each sampling date. Error bars correspond to the standard deviation calculated for 3 replicates.

Proportion of CRing in the CO2 evolved during the 10 day incubation of C.necator JMP134 in the control (white circles) and sand (gray circles) microcosms. Error bars correspond to the standard deviation calculated for 3 replicates. Dash line represents the proportion of CRing in the substrate (2,4-D) used.

Evolution of the cyclopropyl/precursor ratio (cycC17:0 + cycC19:0/C16:1ω9c + C18:1ω9c) with time.

The international 4 per 1000 initiative aims at supporting states and non-governmental stakeholders in their efforts towards a better management of soil carbon (C) stocks. These stocks depend on soil C inputs and outputs. They are the result of fine spatial scale interconnected mechanisms, which stabilise/destabilise organic matter-borne C. Since 2...

In this study we evaluated CO2 emissions during composting of green wastes with clay and/or biochar in the presence and absence of worms (species of the genus Eisenia), as well as the effect of those amendments on carbon mineralization after application to soil. We added two different doses of clay, biochar or their mixture to pre-composted green w...

The aim of the international "4 per 1 000" initiative is to support States and non-governmental actors in their efforts towards a better management of carbon (C) stocks in soils. These stocks depend on the inputs and outputs of C in soils. Stocks are the result of interconnected mechanisms acting at fine spatial scales, leading to stabilisation/des...

Cost-effective and environment-friendly pretreatments, such as fungal pretreatments, are required for anaerobic digestion of lignocellulosic biomass particularly because the amount of methane production is often limited by the lignin content. Anaerobic digestibility is estimated using a Biochemical Methane Potential (BMP) test, which lasts several...

We identified and quantified specific biomarkers of shoots and roots (cutin and suberin-derived compounds, respectively) of three grassland species (Dactylis glomerata L., Festuca arundinacea Schreb. and Lolium perenne L.) in soil under different land use (grass, crop and bare soil) of the SOERE-ACBB experimental site in Lusignan (France). We also...

In this study we evaluated CO2 emissions during co-composting and co-vermicomposting of green wastes with clay and/or biochar. The stability of the final products as well as their effect on C mineralization in soil have been evaluated. The aim of the study was to test the following hypothesis: (1) interactions between clay and biochar and organic w...

RATIONALEThe efficiency of extraction procedures for the determination of organic compounds in soil may be affected by the presence of the mineral phase. Our aim was to analyse the magnitude of such an effect on both total polysaccharide content and 13C-isotopic signature of the polysaccharides.METHODS After acid hydrolysis of 13C-labelled wheat, s...

Lignin is an aromatic plant compound which decomposes more slowly than other organic matter compounds; however, it was recently shown that lignin could decompose as fast as litter bulk carbon in minerals soils. In alpine Histosols, where organic matter dynamics is largely unaffected by mineral constituents, lignin may be an important part of soil o...

For the last decades, the fate of lignins in soil was analyzed mainly with cupric oxide (CuO) oxidation, which is traditionally used to quantify soil lignin content and characterize its state of degradation. This method presents limitations due to incomplete depolymerization of the lignin structure. In this study, we used a physicochemical soil lig...

Land application of exogenous organic matter (EOM) of residual origin can help to maintain or increase soil organic carbon (SOC) stocks. However, it remains necessary to quantify and predict the soil C accumulation and to determine under which form the C accumulates. Changes to the chemical composition of soil organic matter (SOM) after repeated a...

Recent investigations have shown macromolecules, such as cutins, and suberins as effective markers for above and belowground plant tissues. These biopolyesters contain structural units specific for different litter components and for root biomass. The aim of this work was to understand the fate of plant organic matter (OM) in Mediterranean forest s...

C-13 contents of organic matter are changing during decomposition of plant material and stabilization as soil organic carbon (SOC). In this context, several studies showed C-13 enrichment in soil as compared to vegetation for C-3 forests, whereas depletion of C-13 was frequently reported for C-4 grassland soil as compared to C-4 vegetation. These c...

Forest-to-pasture conversion has been reported to increase soil organic matter (SOM) in mineral topsoils in the tropical mountain rainforest region of south Ecuador, with subsequent decreases following pasture abandonment. Until now the mechanisms behind these changes have not been fully understood. To elucidate their varied preservation patterns,...

The objective of this investigation was to test gas-chromatographic compound-specific analysis for studies on the isotopic composition of (13)C-enriched sugar molecules. The effects of (13)C enrichment and type of sugar (C5, C6) will provide valuable information on isotopic correction for future studies employing (13)C-enriched sugars. Five sugar s...

Soil microorganisms play a pivotal role in soil organic matter (SOM) turn-over and their diversity is discussed as a key to the function of soil ecosystems. However, the extent to which SOM dynamics may be linked to changes in soil microbial diversity remains largely unknown. We characterized SOM degradation along a microbial diversity gradient in...

Cutin and suberin structural units might be stabilized in subsoils and contribute to the aliphatic structures observed in stabilized soil organic matter (SOM). We studied their dynamics in subsoils by measuring the concentrations and 13C contents of cutin and suberin markers in soil profiles under wheat (C3) and after 9years of maize cropping (C4 p...

Cutins of plant shoots and suberins, mostly present in roots could contribute to significant portions of stable soil organic matter. Their biomarker potential, residing in their unique compositions in different plant types, has been used previously to infer sources of organic matter in sediments. These aliphatic plant biopolyesters contain specific...

The soil microbial biomass (SMB) is known to participate in key soil processes such as the decomposition of soil organic matter (SOM). However, its contribution to the isotopic composition of the SOM is not clear yet. Shifts in the 13C and 15N natural abundances of the SMB and SOM fractions (mineralised, water soluble and non-extractable) were inve...

Biogeochemistry ISI Document Delivery No.: 823MJ Times Cited: 0 Cited Reference Count: 22 Derrien, Delphine Dignac, Marie-France Dudal, Yves Springer Dordrecht

Understanding the nature of organic matter is a necessary first step in assessing contaminant bioavailability and allowing water supply managers to optimise the treatment train in the aim of providing safe and inexpensive drinking water. This study provides further insight into the composition, structure and functional groups of dissolved organic m...

Combining lipid biomarker profiling with stable isotope probing (SIP) is a powerful technique for studying specific microbial populations responsible for the degradation of organic pollutants in various natural environments. However, the presence of other easily degradable substrates may induce significant physiological changes by altering both the...

Van Soest fractionation is widely employed to characterize exogenous organic matter. The soluble fraction of Van Soest fractionation (SOL, extracted using hot water and then neutral detergent) often increases in line with compost maturity, although it is generally considered as labile. We have developed an alternative extraction method that compris...

Lignins are amongst the most studied macromolecules in natural environments. During the last decades, lignins were considered as important components for the carbon cycle in soils, and particularly for the carbon storage. Thus, they are an important variable in many soil–plant models such as CENTURY and RothC, and appeared determinant for the estim...

The turnover of soil organic matter (SOM) is generally studied in the topsoil horizons, where the highest concentrations of organic carbon (OC) are found. Subsoils, although containing lower amounts of organic carbon compared to topsoils, greatly contribute to the total carbon stocks within a soil profile. An increase in SOM aliphaticity was observ...

Cutins and suberins are biopolyesters that have been suggested to significantly contribute to the stable pool of soil organic matter (SOM). They might be used as tracers for the above- or belowground origin of plant material. The aim of this study was to evaluate the dynamics of shoot and root-derived biomarkers in soils using a wheat/maize (C3/C4)...

To evaluate the qualitative and quantitative information obtained through three commonly used methods for cutin analysis in plants and soils (saponification, CuO oxidation and transmethylation) and understand the chemical mechanisms involved during the depolymerisation, we compared the three methods using a sample of maize leaves, where cutin might...

The aliphatic biopolyesters cutins and suberins have been suggested to significantly contribute to the stable pool of soil organic matter (SOM), and to be tracers for the above- or belowground origin of plant material. Contrary to other plant-derived aliphatic molecules found in the lipid fraction of soils, the stable isotope derived estimates of t...

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Here we present the first results of the DynaMOS project whose main issue is the build-up of a new generation of soil carbon model. The modeling will describe together soil organic geochemistry and soil carbon dynamics in a generalized, quantitative representation. The carbon dynamics time scale envisaged here will cover the 1 to 1000 yr range and...

The contribution of particle-size fractions to carbon (C) and nitrogen (N) mineralization of sludge compost was investigated. Particle-size fractionation was performed using "dry" (sieving of total dry compost) and "wet" (dispersion of compost in water, followed by sieving) fractionation methods, then C and N mineralization of the separated fractio...

This study investigates if Araucaria forest (C3 metabolism) expansion on frequently burnt grassland (C4 metabolism) in the southern Brazilian highland is linked to the chemical composition of soil organic matter (SOM) in non-allophanic Andosols. We used the 13C/12C isotopic signature to group heavy organo-mineral fractions according to source veget...

The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of (13)C-2,4-D (NER15 and NER90, respectively)...

The conversion of grassland into cultivated land is a common agricultural practice, generally leading to the decrease of the soil organic matter (SOM) content. In this study, we analysed quantitative changes in carbon content. Additionally qualitative changes occurring in the soil organic matter composition on a molecular basis were assessed using...

CuO oxidation is traditionally used for soil lignin study, although, like other degradation methods it might give access only to a part of the lignin polymers. For structural characterization, lignins are conventionally isolated from plant material by combining ball-milling, cellulolysis and solvent extraction to recover a milled wall enzymatic lig...

Lignins are amongst the most studied bio-macromolecules in natural environments, for their properties as biomarkers and their suggested influence on soil organic carbon dynamics. A large number of methods exists to characterize lignins, but the alkaline CuO oxidation is the most used for determining lignin fate in soils. The CuO oxidation products...

Lignins are one of the most abundant plant molecules in soils and are considered as having a great impact on the soil organic matter (SOM) content and fate. However, the dynamics and turnover of lignins in soils are not clear on the long-term basis. Some studies suggest that lignins turnover could be faster than that of the bulk SOM (Lobe et al., 2...

Stable Isotope Probing (SIP) is a powerful tool for analysing the fate of pesticides in soil. Together with FAME (Fatty Acid Methyl Esters), it can help identify biodegradation pathways and recycling into the microbial biomass. The fate of ring-labelled 13C-2,4-dichlorophenoxyacetic acid or 2,4-D (C2,4-D) was determined in soil during a 6-month inc...

The biodegradation of nonextractable residues (NER) of pesticides in soil is still poorly understood. The aim of this study was to evaluate the influence of NER ageing and fresh soil addition on the microbial communities responsible for their mineralisation. Soil containing either 15 or 90-day-old NER of 13C-2,4-D (NER15 and NER90, respectively) wa...

CuO oxidation is traditionally used for soil lignin study, although, like other degradation methods it might give access only to a part of the lignin polymers. For structural characterization, lignins are conventionally isolated from plant material by combining ball-milling, cellulolysis and solvent extraction to recover a milled wall enzymatic lig...

Recent in situ13C studies suggest that lignin is not stabilised in soil in its polymerised form. However, the fate of its transformation products remains unknown. The objective of the present research was to provide the first comprehensive picture of the fate of lignin-derived C across its transformations processes: (1) C remaining as undecomposed...

The vegetation of the southern Brazilian highlands in Rio Grande do Sul State is a mosaic of grassland (C4) and deciduous forests (C3) with the conifer Araucaria angustifolia. It was uncertain, whether the grasslands represent relics of drier periods in the Holocene or if they are the result of deforestation in recent times. We analyzed plant tissu...

*INRA UMR Biogéochimie des milieux continentaux Centre de Versailles (FRA) Diffusion du document : INRA UMR Biogéochimie des milieux continentaux Centre de Versailles (FRA)

The use of stable isotope probing of fatty acid methyl esters (FAME-SIP) is a powerful tool to study the microorganisms involved in xenobiotic biodegradation in soil. Nevertheless, it is important to determine how representative these molecules are of microorganisms both qualitatively and quantitatively. Using Cupriavidus necator JMP134 as a simple...

The organic compositions of five different sludges and their residues obtained by neutral detergent extraction (NDF) were characterized by pyrolysis-GC/MS, and the composition of their "soluble" fractions was deduced. These organic characteristics were used to explain the observed mineralization when the sludges were added to a soil under controlle...

The distributions of lignin-derived phenol dimers and cutin/suberin-derived hydroxy carboxylic acids were studied in a single analysis using CuO oxidation of maize leaves and stems as well as the plough layer of a silty soil cultivated with maize. Their relative contributions in soils and plants were compared to that of lignin monomers reported in...

Lignin has long been suspected to be a major source of stable carbon in soils, notably because of the recalcitrant nature of its polyphenolic structure relative to other families of plant molecules. However, lignin turnover studies have produced conflicting results, most of them suggesting that large proportions of plant-residue lignin decompose wi...

Lignin transformation and decomposition products are generally considered a major source of stable soil organic matter (SOM). Nevertheless this process remains poorly understood in part because lignin is a heterogeneous biopolymer composed of several types of phenol monomers, which potentially display specific and contrasting decomposition kinetics...