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PEOPLE@HES-SO – Annuaire et Répertoire des compétences
PEOPLE@HES-SO – Annuaire et Répertoire des compétences

PEOPLE@HES-SO
Annuaire et Répertoire des compétences

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Sauzet Ophélie

Sauzet Ophélie

Compétences principales

Pédologie

Agronomy

Cartographie des sols

Traitement d'images

Préservations des sols

  • Contact

  • Enseignement

  • Recherche

  • Publications

  • Conférences

Contrat principal

Bureau: IRS03

Haute école du paysage, d'ingénierie et d'architecture de Genève
Rue de la Prairie 4, 1202 Genève, CH
hepia
Domaine
Agronomie et économie forestière
Filière principale
Agronomie

ophelie.sauzet@hesge.ch

BSc HES-SO en Agronomie - Haute école du paysage, d'ingénierie et d'architecture de Genève
  • Pédologie appliquée
BSc HES-SO en Agronomie - Haute école du paysage, d'ingénierie et d'architecture de Genève
  • Base de données et bibliographie
BSc HES-SO en Gestion de la nature - Haute école du paysage, d'ingénierie et d'architecture de Genève
  • Pédologie

En cours

Robot autonome pour maraîchage durable
AGP

Rôle: Co-requérant(s)

Requérant(e)s: ReDS

Financement: HES-SO Rectorat

Description du projet : L'objectif du projet est de développer un prototype de robot mobile autonome pour l'arrosage sélectif des plantons. Cette solution allie souplesse et gain de temps. Le robot doit permettre de réaliser l'arrosage des plantons, avec un volume d'eau contrôlé, dans une bande de culture. Celui-ci sera capable de se guider de façon autonome sur le terrain, de détecter le planton et de l'arroser à l'aide d'un bras mécanique. Les fonctionnalités du robot doivent pouvoir être étendues. Nous envisageons p.ex. la possibilité d'effectuer du sarclage (enlèvement mécanique des mauvaises herbes) ce qui permettrait de réduire les intrants chimiques

Equipe de recherche au sein de la HES-SO: Willi Urban , Daniere Pauline , Messerli Etienne , Scherwey Roland , Schroeter Nicolas , Sauzet Ophélie , Stüssi Julien , Dieperink Clément , Olivier Jeremy , Bossoney Luc

Partenaires académiques: ReDS; FR - EIA - Institut iSIS; HEPIA inTECH; HEPIA inTNP; iE

Durée du projet: 01.02.2025 - 31.07.2026

Montant global du projet: 68'200 CHF

Statut: En cours

Programme de soutien au dépôt de projets liés à l'obtention de fonds de tiers ; Prime OFEV - INTRANT.
AGP

Rôle: Requérant(e) principal(e)

Financement: HES-SO Rectorat

Description du projet : Programme de soutien au dépôt de projets liés à l'obtention de fonds de tiers ; Prime OFEV - INTRANT.

Equipe de recherche au sein de la HES-SO: Daniere Pauline , Caloz Thomas , Sauzet Ophélie

Partenaires académiques: HEPIA inTNP

Durée du projet: 04.06.2024 - 31.12.2025

Montant global du projet: 15'000 CHF

Statut: En cours

JC C-Flights Protéger la ressource sol agricole en caractérisant sa couverture végétale par drone

Rôle: Requérant(e) principal(e)

Financement: HES-SO

Description du projet :

FLying for plant cover Identification, plant cover Growth and plant cover Height across Time and Space for Carbon monitoring

La télédétection de la couverture végétale fournit des indications importantes sur la variabilité de la croissance et vise à comprendre les facteurs complexes qui influencent et maximisent la biomasse des cultures. La hauteur est un bon prédicteur de la biomasse, moins spécifique que le NDVI , mais le suivi du taux de couverture du sol est une valeur clé au niveau de la protection des sols et déterminante également. Chaque estimateur a des limites et les techniques d’analyse d'images associées ne peuvent être aujourd’hui déployées par les professionnels du secteur agricole. Le projet évaluera les avantages respectifs des estimateurs et l’efficacité de leur couplage pour estimer la biomasse des cultures intermédiaires. Deux séries de parcelles expérimentales de cultures intermédiaires mélangeant diverses espèces végétales seront survolées par drone lors du printemps et de l’automne 2022 de façon concomitante aux observations réalisées au sol (à, au plus, 4 jours près). Lors des 2 campagnes, les prises de vues seront réalisées à l’aide du matériel suivant mis à disposition par l’inPACT :

-le capteur multispectral Micasense à 5 bandes (R, G, B, Near R, PIR) permettant d’obtenir, après traitement via le logiciel Pix4D, plusieurs indices de végétation tels que le NDVI avec une résolution de 7 cm,

-le capteur optique RGB embarqué SONY RX1RII 42MP avec GPS RTK (Real Time Kinematic) pour fournir la carte de l’estimation des hauteurs de la végétation qui sera générée en calculant la différence entre le modèle numérique de surface du drone et le modèle numérique de terrain LIDAR du Système d'Information du Territoire Genevois (structure from motion based software).

La mesure manuelle de la hauteur, l’estimation visuelle du taux de couverture in situ ainsi que les mesures de biomasse par récolte manuelle seront réalisées et uniquement destinées au calibrage et à la vérification des données récoltées par le drone.

Suite au traitement des images, l’analyse des corrélations (coefficient de corrélation de Pearson et p-value associée) entre les estimateurs obtenus par drone et les vérités terrain concerneront la hauteur d’une part et le taux de couverture d’autre part afin d’évaluer la précision de ces estimations. Ensuite, le meilleur estimateur de la biomasse sera choisi en analysant les corrélations entre la biomasse mesurée in situ et les estimateurs hauteur et taux de couverture pris séparément puis couplés. Le modèle de prédiction de la biomasse obtenu sera ensuite testé pour plusieurs espèces séparément (modèle spécifique) ainsi que pour plusieurs espèces ensemble (modèle global) pour évaluer sa sensibilité à la diversité des espèces végétales présentes dans les cultures intermédiaires. Une fois les limites appréciées, nous serons à même de valider et de transférer une solution facile à utiliser aux organismes de conseil agricole et aux agriculteurs par adhésion à des projets pilotes de séquestration du carbone dans les sols ou de préservation des sols (Programme de protection des ressources OFAG LAgr Art. 77a & b Terres Vivantes).

Ainsi, la méthodologie proposée, qui fait intervenir des aspects « systématiques », devrait assurer le succès du projet.

Equipe de recherche au sein de la HES-SO: Sauzet Ophélie , Dubois Alain

Durée du projet: 01.01.2022 - 31.12.2022

Statut: En cours

Terres Vivantes

Rôle: Collaborateur/trice

Description du projet :

Améliorer la qualité des sols: un projet réalisé pour et par les agriculteurs du Jura

Terres Vivantes (2019-2026) vise à développer la capacité de 90 agriculteurs volontaires (3000 ha de terres arables, JU et BE) à améliorer la qualité de leurs sols par une approche associant autodiagnostic, partage d’expériences et soutien de la recherche. Ce projet cherche ainsi à répondre aux deux premiers défis pour l’avenir posés par l’OFAG (Office Fédéral de l’Agriculture): conserver la qualité des terres agricoles et développer une agriculture efficiente adaptée au lieu de production.

Partenariat(s): 

Agroscope Reckenholz

Université de Neuchâtel

EnviBioSoil

Haute école des sciences agronomiques, forestières et alimentaires (HAFL)

UniNe Ethno

Programme de protection des ressources (OFAG)

Fondation Rurale Interjurassienne (FRI)

Canton du Jura

Canton de Berne

Equipe de recherche au sein de la HES-SO: Sauzet Ophélie

Url du site du projet: https://www.hesge.ch/hepia/recherche-developpement/projets-recherche/en-cours/terres-vivantes

Statut: En cours

Terminés

Programme de soutien au dépôt de projets liés à l'obtention de fonds de tiers ; Prime OFAG - RESULTERRE.
AGP

Rôle: Requérant(e) principal(e)

Financement: HES-SO Rectorat

Description du projet : Programme de soutien au dépôt de projets liés à l'obtention de fonds de tiers.

Equipe de recherche au sein de la HES-SO: Caloz Thomas , Sauzet Ophélie

Partenaires académiques: hepia inTNE

Durée du projet: 11.05.2023 - 31.12.2024

Montant global du projet: 15'000 CHF

Statut: Terminé

2024

The organic carbon-to-clay ratio as an indicator of soil structure vulnerability, a metric focused on the condition of soil structure
Article scientifique ArODES

Ophélie Sauzet, Alice Johannes, Cédric Deluz, Xavier Dupla, Adrien Matter, Philippe C. Baveye, Pascal Boivin

Soil Use and Management,  2024, 40, 2, e13060

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Résumé:

The soil organic carbon to clay ratio (SOC:clay) is a metric used in soil quality management. In Switzerland and the United Kingdom, for example, threshold values for SOC:clay ratios have been determined to indicate very good (>1:8) to degraded (<1:13) soil structures. A recent article in Soil Use and Management by Poeplau and Don, however, suggested that this metric is ‘strongly biased and misleading’, based on their observation that German sandy soils and heavy clay soils tend to show very high and very low SOC:clay ratios, respectively. An alternative metric was proposed based on the ratio of actual SOC to expected SOC level for a considered area. We offer a commentary on the proposal, arguing that because soil structure quality is overlooked by the approach, it fails to provide appropriate SOC levels for soil health and could lead to soils with highly depleted SOC being classified ‘good’. The SOC:clay ratio, on the other hand, does address soil structure condition, providing a structure vulnerability index, a key function independent of local soil management conditions. When soils are found to have high structure vulnerability, as indicated by the SOC:clay ratio, the cropping practices at the site should be investigated and ways to increase the SOC content considered. Structure condition threshold values may only need to be reassessed if it is shown that the average structure quality observed is not in conformity with the present thresholds, which would be expected for some soils, such as Andosols.

2023

Advances in machine vision technologies for the measurement of soil texture, structure and topography
Chapitre de livre ArODES

Jean-Marc Gilliot, Ophélie Sauzet

Dans Biswas, Asim, Lobsey, Craig, Advances in sensor technology ofr sustainable crop production  (62 p.). 2023,  Cambridge, UK : Burleigh Dodds Science Publishing

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Résumé:

This chapter examines advances in machine vision technologies for the measurement of soil texture, structure and topography. It starts by providing an overview of the basic principles of machine vision technologies, focusing on areas such as 3D surface modelling and various methods of soil thin section microscopy. Two case studies are also provided in the chapter to support the main text discussion.

Soil organic carbon content and soil structure quality of clayey cropland soils :
Article scientifique ArODES
a large-scale study in the Swiss Jura region

Alice Johannes, Ophélie Sauzet, Adrien Matter, Pascal Boivin

Soil Use and Management,  2023, vol. 39, no. 2, pp. 707-716

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Résumé:

Soil organic carbon (SOC) fashions soil structure, which is a key factor of soil fertility. Existing SOC content recommendations are based on SOC:clay ratio thresholds of >1:10. However, the corresponding SOC content might be considered hard to reach in clayey soils, whose structure degradation risk is assumed to be high. Here, we analysed the SOC content and soil structure quality of soils under similar cropping practices with clay contents ranging from 16% to 52%. Five undisturbed soil cores (5–10 cm layer) were collected from 96 fields at 58 farms in the Swiss Jura region. We assessed the soil structure quality visually using the CoreVESS method. Gravimetric air content and water content, and bulk density at −100 hPa were also measured, and the soil structure degradation index was calculated. We found that the relationship between SOC and clay content held over the clay content range, suggesting that reaching an acceptable SOC:clay ratio is not limited by large clay contents. This suggests that the 1:10 SOC:clay ratio may remain useful for clayey soils. In contrast to what was expected, it is not more challenging to reach this ratio in clayey soils even if it implies reaching very large SOC contents. SOC content explained the considered physical properties better than clay content. From a soil management point of view, these findings suggest that the soil texture determines a potential SOC content, while the SOC:clay ratio is determined by farming practices regardless of the clay content.

2022

Long-term quantification of the intensity of clay-sized particles transfers due to earthworm bioturbation and eluviation/illuviation in a cultivated Luvisol
Article scientifique ArODES

Ophélie Sauzet, Cécilia Cammas, Jean-Marc Gilliot, David Montagne

Geoderma,  2022, vol. 429, article no. 116251

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Résumé:

As a result of the limited knowledge on eluviation/illuviation and bioturbation rates, these two processes of soil particles translocation are qualitatively described either as synergic or competing processes. Here we take the opportunity of the recent development of an image analysis procedure to quantify illuvial clay and earthworm’s porosity to quantify the intensity of illuviation and bioturbation cumulated over soil formation in a temperate cultivated Luvisol. The key objectives of the study are i) to quantify the total intensity of illuviation and bioturbation and their depth distributions and ii) to assess the possibility for bioturbation to limit or compensate the depletion of the clay-sized fraction in topsoil horizons due to eluviation. The total quantity of illuvial clay is 1,100 t.ha−1 while the estimated annual amount of clay-sized fraction translocated by eluviation is between 0.08 and 1 t ha−1 yr−1. This is comparable to the annual loss of land by water erosion (between 1 and 5 t ha−1 yr−1) or by arable erosion (3.3 t ha−1 yr−1). Eluviation/illuviation is thus a discrete and active form of soil loss. With approximately 1,900 t.ha−1 of clay-sized fraction, the amount of fine particles displaced at least once by bioturbation is higher than the one related to eluviation/illuviation. At first sight, it therefore seems possible for biological activity to compensate for vertical transfers of the clay-sized fraction by eluviation/illuviation. However, our study shows that a considerable amount of the clay-sized fraction will never be brought up by the bioturbation and will remain definitively lost for the surface horizons as bioturbation decreases non-linearly with depth. Consequently, a preventive management of the depletion of the clay-sized fraction in topsoil horizons by eluviation/illuviation should be preferred to the curative management of its consequences by bioturbation.

2021

Nicodrilus nocturnus and Allolobophora icterica drill compacted soils but do not decrease their bulk density – A laboratory experiment using two contrasted soils at two different compaction levels
Article scientifique ArODES

Ophélie Sauzet, Roxane Kohler-Milleret, François Füllemann, Yvan Capowiez, Pascal Boivin

Geoderma,  2021, vol. 402, article no. 115164

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Résumé:

Earthworms are known to play an important role in soil processes, especially in the regeneration of soil structure. However, quantitative studies about their role on soil physical properties are still scarce. In this study the effects of two earthworm species (Nicodrilus nocturnus as anecic, Allolobophora icterica as endogeic) following three treatments (N. nocturnus only, A. icterica only and both species with 80% weight of N. nocturnus and 20% of A. icterica) on soil specific volumes and pore properties are evaluated in mesocosms (30 cm height and 15 cm diameter) for a loamy Anthrosol and a silt loam Luvisol. The soils were repacked to bulk density observed in the field (1,15 and 1,25 g cm−3 respectively) and to compacted bulk density (1,4 and 1,5 g cm−3 respectively). Except earthworm-free controls, introduced earthworm biomass was close to 500 g.m−2. The experiment lasted 23 weeks, under constant temperature and soil matrix potential, and earthworms were fed with hay. The impact of earthworms on soil porosities and specific volumes was assessed using (i) computed tomography on mesocosm and (ii) shrinkage analysis on undisturbed cubic samples (150 cm3). Anecic surface cast bulk density was determined after wax coating. At mesocosm scale, the specific volume of compacted soils increased significantly with the anecic and mixed earthworm treatments (+1.9% for the Anthrosol and +2.6% for the Luvisol), while no change was observed with endogeics regardless of the initial level of compaction or the soil type. After subtracting the burrow volumes, the remaining soil matrix specific volume showed significant decrease with earthworms in case of loose soils, particularly with endogeics with 5.6% decrease of the specific soil matrix volume, while the compacted soil matrix was not decompacted. At undisturbed cubic sample scale, shrinkage analysis confirmed these observations with earthworms decreasing the larger structural pores and promoting a more rigid plasma. Anecic surface casts showed intermediate bulk density (0.82 cm3 g−1 for the Anthrosol and 0.73 cm3 g−1 for the Luvisol) between compacted (0.73 cm3 g−1 for the Anthrosol and 0.67 cm3 g−1 for the Luvisol) and loose (0.88 cm3 g−1 for the Anthrosol and 0.81 cm3 g−1 for the Luvisol) soil matrices. We concluded that the decompaction effect of earthworms was due to the opening of burrows at mesocosm soil scale, while the matrix volume was i) either compacted in case of loose soil especially with endogeics at the expense of the >150 µm equivalent radius structural pores or ii) unchanged in case of compacted soil. Our results support the conclusion that earthworms alone cannot regenerate the matrix of compacted soils and even compact the soil matrix in case of loose soils.

Changes in topsoil organic carbon content in the Swiss leman region cropland from 1993 to present. Insights from large scale on-farm study
Article scientifique ArODES

Xavier Dupla, Karine Gondret, Ophélie Sauzet, Eric Verecchia, Pascal Boivin

Geoderma,  2021, vol. 400, article no. 115125

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Résumé:

Increasing cropland topsoil organic carbon (SOC) content is a key goal for soil improving quality and adaptating soils to climate change. Moreover, the short term potential of climate mitigation by carbon sequestration is mostly attributed to increasing topsoil SOC content (Balesdent and Arrouays, 1999, Chambers et al., 2016; Minasny et al., 2017; Balesdent et al., 2018). However, the possibility to increase SOC content is highly disputed in current literature which is mostly based on field experiments. We quantified the on-farm SOC content deficit and SOC content change rate of cropland topsoil (0–20 cm) from western Switzerland using the data bases of Geneva and Vaud cantons containing more than 30,000 topsoil analyses, performed every ten years on every cultivated field of the region since 1993. SOC deficit was estimated as the amount of SOC necessary to reach the 0.1 SOC:clay ratio considered as the minimum required SOC amount for acceptable soil quality. Cropland topsoils of the Vaud and Geneva cantons displayed a 20% and 70% SOC content deficit, respectively. In both cantons, the range of observed rates of change in SOC content from 1993 to present was very large, from −30 to +30‰ per year, with a median value of 0. However, the time trends showed a highly significant linear increase of rates from −5‰ to +6‰ per year on average, in 1995 and 2015, respectively, with no change in SOC content reached by 2005–2007. These trends were attributed to the Swiss agri-environmental schemes applied at the end of 20th century, namely mandatory cover crops and minimum rotations of 4 crops. Further, SOC content increase was accordant with the continuing adoption of minimum tillage, conservation agriculture and multi-species intense cover crops. These findings oppose to those obtained in Swiss long-term experiments, which emphasizes the need to use on-farm information when adressing agriculture policy, climate mitigation or soil quality management issues.

Comparison of empirical and process-based modelling to quantify soil-supported ecosystem services on the Saclay plateau (France)
Article scientifique ArODES

Pauline Choquet, Benoit Gabrielle, Maha Chalhoub, Joël Michelin, Ophélie Sauzet, Ottone Scammacca, Patricia Garnier, Philippe C. Baveye, David Montagne

Ecosystem Services,  2021, vol. 50, article no. 101332

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Résumé:

Following the rapid development of models to assess and map ecosystem services (ES) in the last decades, there is an increasing need for comparative studies testing their efficiency and accuracy against field data. The representation of soils in these models is often oversimplified and remains a major source of uncertainty in ES assessment and mapping. In this context, a first objective of the present article is to develop two approaches of increasing complexity (empirical versus process-based) integrating a realistic representation of soils, to map two provisioning (biomass and water) and two regulating (water quality and global climate) soil-supported ES on the Saclay plateau (France). A second objective is to compare them according to their relative ability to replicate direct measurements (absolute accuracy) in a cultivated soil and to translate gradients in soil properties into differences in levels of the soil-supported ES (relative accuracy). On the basis of currently available models, the soil-supported ES can be assessed only under a homogeneous simplified crop rotation. For the fixed land management used in this research, the soil type significantly influences the levels of the considered services. The process-based modelling is effective only in deep, homogeneous, and cultivated soils. By contrast, the empirical modelling is effective over a larger range of soils, but mostly for provisioning services. The ability to integrate a realistic representation of soils in ES assessment and mapping with common tools and models is currently limited in terms of land-use, soil diversity, or types of ES. Increasing the accuracy of ES assessment and mapping requires pursuing the effort towards developing and validating models that explicitly take into account soil processes and properties.

ACS et teneur en matière organique du sol :
Article professionnel ArODES
quelques enseignements tirés de la région lémanique

Pascal Boivin, Xavier Dupla, Téo Lemaître, Karine Gondret, Ophélie Sauzet, Éric Verrecchia

Techniques culturales simplifiées (TCS) : agronomie, écologie et innovation,  2021, no. 111, pp. 18-25

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Résumé:

L’agriculture de conservation des sols (ACS) n’est pas née avec la découverte du changement climatique. Elle est née de la volonté d’agriculteurs de préserver et de restaurer leurs sols et elle s’est développée en marge des politiques publiques. L’initiative 4-pour-mille (https://www.4p1000.org/fr) met en avant l’ACS comme solution de premier plan pour séquestrer le carbone dans les sols (figure 1), ce qui a suscité une grande production d’articles scientifiques et de prises de position, tant pour soutenir cette option que pour en souligner les faiblesses. Il en résulte des controverses et des affirmations probablement illisibles pour la plupart des acteurs. Cet article, s’appuyant sur les résultats de nos recherches, vise à apporter quelques éclaircissements sur les enjeux liés à la teneur en matière organique des sols en agriculture, notamment les enjeux climatiques, et les apports de l’ACS, à travers un retour d’expérience à grande échelle sur la région lémanique (cantons suisses de Vaud et Genève).

2020

Bypass and hyperbole in soil science :
Article scientifique ArODES
a perspective from the next generation of soil scientists

Xavier Portell, Ophélie Sauzet, Maria Balseiro-Romero, Pascal Benard, Rémi Cardinael, Estelle Couradeau, Dieudonné D. Danra, Daniel L. Evans, Ellen L. Fry, Edith C. Hammer, Danielle Mamba, Luis Merino-Martin, Carsten W. Mueller, Marcos Paradelo, Frédéric Rees, Lorenzo M. W. Rossi, Hannes Schmidt, Laura S. Schnee, Charlotte Védère, Alix Vidal

European Journal of Soil Science,  2020, vol. 72, no.1, pp. 31-34

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Résumé:

We, the co‐authors of this letter, are an international group of soil scientists at early career stages, from PhD students to postdoctoral researchers, lecturers, and research fellows with permanent positions. Here, we present our collective musings on soil research challenges and opportunities and, in particular, the points raised by Philippe Baveye (Baveye, 2020a, 2020b) and Johan Bouma (Bouma, 2020) on bypass and hyperbole in soil science. Raising awareness about these issues is a first and necessary step. To this end, we would like to thank Philippe Baveye and Johan Bouma for initiating this debate. The so‐called “rat‐race” in the scientific publication system, and the associated practices including “bypass” and “hyperbole” as highlighted by Baveye (2020a, 2020b), particularly affect the ability of early career soil scientists to begin and consolidate their careers and to make meaningful contributions to their disciplines. PhD students, postdoctoral researchers, junior and senior lecturers and well‐established professors hold contrasting perspectives on these issues and unequally suffer from the pernicious impacts and imperfections of the current system. We strongly believe that finding and implementing effective and efficient solutions to adjust the system requires the involvement and collective responsibility of the whole soil science community.

Evaluation of the potential for soil organic carbon content monitoring with farmers
Article scientifique ArODES

Cédric Deluz, Madlene Nussbaum, Ophélie Sauzet, Karine Gondret, Pascal Boivin

Frontiers in Environmental Science,  2020, vol. 8, article no. 113

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Résumé:

Increasing soil organic carbon (SOC) content is crucial for soil quality and climate change mitigation. SOC monitoring is indispensable to the corresponding policies and should provide results at farm scale to allow for incentives. In Switzerland, farmers perform mandatory analyses of the SOC content of the 0–20 cm topsoil of every field, based on a composite sample, at least every 10 years. The corresponding results are stored in a database in canton of Geneva. These data may be relevant for topsoil SOC monitoring, in particular for carbon sequestration policies, provided that they show appropriate quality, which is analyzed in this study. The minimum detectable change (MDC) of past results calculated based on the observed SOC changes was 0.013% g g–1 at canton scale (2,700 fields). Based on extended sampling of three representative fields, different sampling strategies were simulated to determine the best future sampling guidelines for farmers. Collecting 20 aliquots with a gouge on the field diagonals was considered the best sampling compromise with field MDC of ∼0.1% g g–1 and a sampling duration of 20 min. Compared to this procedure, former farmers’ sampling was not biased in average but showed a variance of 0.22% g g–1 due to smaller number of aliquots and varying sampling depths. Based on the best sampling results and assumptions on farm-scale SOC variance or SOC differences, the MDCs at farm scale ranged from 0.21 to 0.12% g g–1 (5 fields) and 0.09 to 0.05% g g–1 (30 fields), respectively. These MDCs are small compared to published monitoring networks MDCs and allow determining SOC change rates at farm scale, thus offering perspectives for inexpensive and efficient monitoring in the frame of soil quality or climate mitigation incentives. For the latter, however, additional information with equivalent soil mass and deeper-layer carbon content would be necessary.

2019

Upward mercury transfer by anecic earthworms in a contaminated soil
Article scientifique ArODES

Tania Ferber, Vera I. Slaveykova, Ophélie Sauzet, Pascal Boivin

European Journal of Soil Biology,  2019, vol. 91, pp. 32-37

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Résumé:

Mercury (Hg) is a contaminant of global importance but its fate and impact in soils is overlooked. Earthworms are responsible for soil bioturbation but their interaction with Hg is poorly described. This study was conducted on a Hg contaminated site in Switzerland. The objectives were to determine the Hg tolerance of Lumbricus terrestris and Aporrectodea nocturna, and their capability to redistribute Hg from deep contaminated soil layers to remediated topsoil layers. Earthworms were incubated for 30 days in 35 cm height soil columns with soil Hg contents ranging from 0.19 to 83 mg Hg kg−1. 100% survival was observed except for the highest soil concentration (67% survival). Corresponding bioaccumulation factors ranged from 1 to 17. In parallel, Hg upward transfer by earthworms from a deep contaminated soil layer to a non-contaminated 40 cm thick surface layer was studied in 80 cm repacked soil columns. After 70 days, total Hg content of surface casts was 10 times higher than the non-contaminated soil. Furthermore, the 25–30 and 35–40 cm layers had a Hg content of 0.537 and 8.54 mg Hg kg−1 respectively, both exceeding the local threshold intervention value of 0.5 mg Hg kg−1. We concluded that (i) earthworms not acclimated to polluted soils can survive Hg levels as high as 85 mg Hg kg−1 in mesocosms, and (ii) a 40 cm thick remediated layer would be recontaminated after 6 months of earthworm activity if the underneath layer remained contaminated.

2017

Development of a novel image analysis procedure to quantify biological porosity and illuvial clay in large soil thin sections
Article scientifique

Sauzet Ophélie

Geoderma, 2017 , no  292, pp.  135-148

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2022

Soil structure quality and biodiversity across a range of different practices and tillage intensities
Conférence ArODES

Ophélie Sauzet, Alice Johannes, Renée-Claire Le Bayon, Luc Scherrer, Pascal Boivin

Proceedings of the EGU General Assembly 2022, 23-27 May 2022, Vienna, Austria

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The effects of switching spatial scales on soil-based ecosystem services levels and patterns :
Conférence ArODES
a case study at the patch scale

Ottone Scammacca, Pauline Choquet, Benoit Gabrielle, Joel Michelin, Patricia Garnier, Philippe Baveye, David Montagne, Ophélie Sauzet

Proceedings of the EGU General Assembly 2022, 23-27 May 2022, Vienna, Austria

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2021

ORGANIC CARBON SEQUESTRATION POTENTIAL, RATE AND ASSOCIATED PRACTICES, AS OBSERVED IN SWISS ARABLE LAND
Conférence

Boivin Pascal, Sauzet Ophélie, Xavier Dupla, Gondret Karine, Téo Lemaitre, Eric Verrecchia, Stéphanie Grand

Eurosoil 2021, 23.08.2021 - 27.08.2021, Genève

INDICATORS AND FRAMEWORK FOR A RESULT-ORIENTED MANAGEMENT SCHEME OF SOIL QUALITY IN ARABLE LAND
Conférence

Boivin Pascal, Gondret Karine, Sauzet Ophélie

Eurosoil 2021, 23.08.2021 - 27.08.2021, Genève

Peut-on définir un niveau souhaitable de MO dans les sols ?
Conférence

Boivin Pascal, Sauzet Ophélie

Webinaires de la COMIFER, 07.04.2021 - 12.10.2023, Viio conférence et Paris

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2020

Organic carbon sequestration potential, rate and associated practices, as observed in Swiss arable land
Conférence ArODES

Pascal Boivin, Xavier Dupla, Ophélie Sauzet, Karine Gondret

Proceedings of EGU General Assembly 2020, 4-8 May 2020

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2019

Earthworms drill the compacted soil but do not decrease its bulk density - a laboratory experiment using two contrasted soils
Conférence

Sauzet Ophélie

EGU General Assembly 2019, 01.04.2019 - 01.04.2019, Vienne

2018

Soil quality monitoring by farmers in the frame of a result-oriented scheme :
Conférence ArODES
the case of Swiss arable land

Ophélie Sauzet, Karine Gondret, Alice Johannes, Pascal Boivin

Proceedings of 21st ISTRO (International Soil Tillage Research Organization) International Conference, 24-27 September 2018, Paris, France

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