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Effets de l’apport de digestat de méthanisation et des cultures hivernales sur les flux de carbone dissous et la composition de la matière organique dissoute du sol
No full textSoil dissolved organic matter (DOM) is mobile, reactive and originates from a variety of sources that determine its concentration, its chemical composition, and thus its fate. In the soil-plant-digestate system, the contribution of the different components to DOM, notably via rhizodeposition and the input of persistent molecules from anaerobic digestion, has been overlooked. Although digestate storage is widespread, its effects on the DOM pool have not been much studied.Dissolved organic (DOC) and inorganic carbon concentrations and fluxes were measured for a mineral fertilizer, pig slurry and digestate from this slurry using the SOERE PRO lysimeters under two winter crops (wheat and mustard) for 9 years.In the organo-mineral horizon, the DOC concentration is higher for the digestate than for the pig slurry and is modulated by the crop development: at the beginning of the drainage season for mustard and in the middle of the season for wheat. This synergy between digestate (biostimulant effect on rhizodeposition) and crops (desorption of persistent molecules from digestate by soil alkalinization) also influences the composition of DOM analyzed by thermochemolysis, chromatography and mass spectrometry. In the mineral horizon, there is no quantitative difference between treatments. A significant sorption of aromatic compounds is suggested for the digestate modality. These results observed in the field could not be reproduced under controlled conditions. Digestate storage reduces the amount of persistent molecules in DOM analyzed by 3D fluorescence.Les concentrations et flux de carbone organique (COD) et inorganique dissous ont été mesurés pour les modalités de fertilisation minérale, lisier et digestat de ce lisier via le dispositif lysimétrique du SOERE PRO sous deux cultures hivernales (blé et moutarde) pendant 9 ans. Dans l’horizon organo-minéral, la concentration du COD est plus élevée pour le digestat que pour le lisier et est modulée par le développement de la culture : en début de saison de drainage sous moutarde et en milieu de saison sous blé. Cette synergie entre digestat (effet biostimulant sur la rhizodéposition) et cultures (désorption de molécules persistantes du digestat par alcalinisation du sol)influence également la composition de la MOD analysée par thermochimiolyse, chromatographie et spectrométrie de masse. Dans l’horizon minéral, il n’y a aucune différence quantitative entre traitements. Une sorption importante des composés aromatiques pour la modalité digestat est suggérée. Ces résultats observés au champ n’ont pas pu être reproduits en conditions contrôlées. Le stockage du digestat diminue la quantité de molécules persistantes dans la MOD analysée par fluorescence 3D
A comprehensive dataset of near infrared spectroscopy measurements to predict Nitrogen and Carbon contents in a wide range of tissues from Brassica napus plants grown under contrasted environments
No full textInternational audienceWinter oilseed rape (WOSR, Brassica napus L.) is the third largest oil crop worldwide that also provides a source of high quality plant-based proteins. Nitrogen (N) and carbon (C) play a key role in plant growth. Determination of N and C contents of plant tissues throughout the growth cycle is crucial in2assessing plant nutritional status and allowing precise input management. In the dataset presented inthis article, 2427 WOSR samples arising from a large diversity of tissues collected on WOSR diversitywere analyzed by near infrared spectroscopy from 4000 to 12000 cm-1. At the same time, referencechemical data for the N and C contents of the same samples were determined by elemental analysisusing the Dumas method. Partial least squares regression has been used to develop predictive modelslinking spectral and chemical data, so that new samples can be characterized without the need forreference methods. This dataset could be used to test new calculation algorithms in order to enhanceprediction performance or for training purposes. These models can be used as a rapid method fordetermining N and/or C content, adding to decision-support tools for fertilizer application throughoutthe plant developmental cycle
Organisation méso-échelle et fonctionnement trophique du l'écosystème benthique du Golfe de Gascogne
No full textInternational audienceMarine shelves are highly productive ecosystems where benthic communities play an important role in food webs, particularly in the Bay of Biscay (BoB). Knowledge of the structural and functional characteristics of these communities can facilitate the understanding of the functioning of this ecosystem in response to environmental forcings. Previous works in the 60s on the northern part of the BoB have already shown the role of sediment and thermal depth gradient on the spatial organization of the macrobenthic component. The recurrent EVHOE survey of the French part of the shelf provides data on epibenthic megainvertebrates and bentho-demersal fish, two other biological components of this ecosystem. The study of their characteristics can account for environmental forcings and ecological processes operating at the mesoscale (10 to 100 km). This was accomplished in this work using taxonomic and functional approaches over a 12y dataset (2008-2020 data), and also by the assessment of epibenthic megainvertebrates production.Based on species composition, structural parameters and the high significant correlation (68%) between the respective spatial organizations of the two biological components (fish and invertebrates), seven distinct benthic areas, referred to as "benthiscapes”, were recognized. They were distributed from the coast to the shelf break and extending from the north to the south of the BoB. The spatial organization of both components were mainly correlated to meso-scale environmental forcings such as river plumes and bottom current velocities. The epibenthic megainvertebrates revealed distinct functional differences between benthiscapes, with a prevalent carnivorous dominance observed in disturbed areas affected by fishing activity or estuarine influence, contrasted with an increased deposit feeding activity near shelf break upwellings. Productions were notably higher in the former areas. This indicates that primary production, stimulated by nutrients supplies from rivers or deep waters, plays a key role in the spatial organisation of the observed benthic trophic dynamics and functioning
A survey on young post-graduated farmers: profiles, motivations, and difficulties
No full textISBN : 979-12-210-6769-9International audienceThe French agricultural sector is currently facing a major challenge in terms of renewal of generations. With 25% of French farmers set to retire before 2030, the setting-up of new farmers is crucial. The present study focused on farmers who obtained a master’s degree and started their activity for less than 10 years. Forty-one of them were identified by alumni network and surveyed by master 2 students of the Institut Agro Rennes-Angers. Qualitative semi-structured interviews were performed using a pre-established interview guide. Four profiles (groups A, B, C and D) of farmers were established based on their motivations for setting up, using multiple correspondence analysis (MCA). Group A (n = X) was motivated by the desire to play an active role in promoting healthy production, mostly with on-farm processing and direct-sales. Group A included breeders set up outside the family, choosing local breeds. Group B were motivated to maintain the family farm (n = X). They were not involved in certified production; they reported limited holiday time (< 7 days/year) and use more outsourcing than other profiles. Group C (n = X) expressed optimism about the future of farming. They set up independently, they employed staff to manage farm operations and were partially satisfied with their income. Group D (n = X) primarily sought challenges in their live and were mainly specialised in monogastric species. Overall, results from this study may provide insights to facilitate future setting-ups from these profiles. A positive aspect in this study is that these master’s graduate farmers demonstrated a strong willingness to exchange and share their experience
Effect of using germinated and fermented lupin and oats as a dietary protein source on laying hen performance and egg quality
No full textInternational audienceSoybean meal is the dominant protein source for poultry nutrition. However, soybean is not widely grown in Europe, necessitating importation from other countries. To reduce dependency on imported soybean meal, an alternative feed material is needed. Fermentation and/or germination of grains are known to increase the value of the protein content of a diet. This study aimed to determine if they could substitute partly soybean meal in a diet. Germinated or fermented or germinated and fermented grains of lupin and oats were used in laying hen's diet (a mix of 6.50% lupin and 3.50% oat grains). Oats were dehulled or not dehulled. The hens' weight loss and the downgraded eggs rate were the lowest when using fermented grains. All trial diets reduced the egg cholesterol content. Dehulling had only a slight effect on performance. Diets containing germinated grains led to a decrease in laying performance and an increase in body weight loss. Diets containing fermented grains gave the best results in terms of quantity of amino acids, hen weight maintenance, laying performance, and egg quality. In conclusion, fermented lupin and oats can be used in laying hen diets to partly substitute sources of protein such as soya, but germinated grains cannot
Vers une meilleure compréhension de la vision des apprenants de leur enseignement et de leur lien au numérique : résultat d'une enquête pré-confinement
No full textInternational audienceDepuis la démocratisation du numérique, l'enseignement supérieur connaît une mutation sans précédent. Les apprenants se forment désormais à toute heure, en tout lieu et avec de multiples outils. Pour autant, le besoin de proximité entre pairs et avec les enseignants est toujours aussi présent, ce qui peut paraître contradictoire avec l'idée d'un enseignement 100 % à distance.Quelles sont les attentes des apprenants vis-à-vis de l'enseignement supérieur pour les années à venir ? Cet article fait le bilan d'une étude qualitative menée auprès de 33 étudiants de 13 établissements de l'enseignement supérieur en agroalimentaire français avant la crise de la COVID-19. En complément, 178 lycéens ont répondu à un questionnaire destiné à mieux comprendre leurs habitudes d'apprentissage à l'ère digitale. L'ensemble permet de proposer des clés pour envisager l'évolution de l'enseignement supérieur de manière avertie : l'adaptation des formations au contexte professionnel, leur individualisation grâce au numérique et au maintien d'un lien présentiel avec l'enseignant. Il montrera notamment tout Vers une meilleure compréhension de la vision des apprenants de leur enseignement 2 l'intérêt de s'orienter vers une hybridation raisonnée des enseignements pour lever les risques et les craintes perçus par les apprenants</p
CAP 2023-2027: A lever for transforming French agriculture?
No full textCommon Agricultural Policy 2023-2027 A lever for transforming French agriculture or a missed opportunity in the face of climate and environmental challenges?Carrefour de l'innovation agronomique on Thursday 4 May 2023 Institut Agro Rennes-Angers, Rennes campusInternational audienceThe reform of the Common Agricultural Policy (CAP) 2023 has essentially introduced methodological change, with greater subsidiarity for Member States (MS), who are responsible for drawing up their own National Strategic Plan (NSP), in line with their national priorities, but committing their state to contributing to European objectives
Avis de l'Anses relatif à « la catégorisation de Amasa parviseta »
No full textCitation suggérée : Anses. (2024). Catégorisation de Amasa parviseta. (saisine 2023-SA-0028). Maisons-Alfort : Anses, 22 p.Dans le cadre de la surveillance des organismes réglementés ou émergents (SORE), un dispositif de piégeage a été déployé par la DGAL en 2021 avec l’appui de l’INRAE et de l’ONF. L’objectif de ce dispositif est d’effectuer une surveillance passive dans les sites d’entrée potentiels (ports, aéroports, marché d’intérêt national (MIN)) des organismes réglementés ou émergents (SORE). Ce piégeage est qualifié de « large spectre » car il peut concerner plusieurs filières de production suivies dans le cadre de la SORE (forêts, jardins et espaces verts et infrastructures (JEVI), arboriculture fruitière) en ciblant cependant majoritairement les insectes coléoptères des ligneux. Les principes de la surveillance mise en œuvre s’appuient sur les résultats précédemment acquis dans le cadre du projet PORTRAP, utilisant des pièges génériques multi-composés pour la détection précoce d’insectes exotiques xylophages dans les sites potentiels d’entrée sur le territoire national. Les pièges ont été disposés sur 13 sites (7 ports maritimes, 1 port fluvial, 4 aéroports et 1 marché national) dispersés sur le territoire (France métropolitaine continentale). Au total 9279 individus appartenant à 110 espèces différentes ont été capturés. Aucune espèce d’insecte de quarantaine prioritaire n’a été piégée. En revanche, la présence d’individus appartenant à 8 espèces de coléoptères exotiques, a priori non présents sur notre territoire, des familles Cerambycidae et Curculionidae (sous-familles des Scolytinae et Platypodinae) a été relevée. Les 8 espèces d’insectes exotiques sont les suivantes : - Cerambycidae : Cordylomera spinicornis (Fabricius, 1775), Trichoferus campestris (Faldermann, 1835), Xylotrechus chinensis (Chevrolat, 1852), Xylotrechus stebbingi Gahan, 1906 ; - Curculionidae : Amasa sp. near truncata, Euplatypus hintzii (Schaufuss, 1897), Euplatypus parallelus (Fabricius, 1801), Xyleborus affinis Eichhoff, 1868
Molecular responses of chicken embryos to maternal heat stress through DNA methylation and gene expression
No full textAbstract Climate change, with its repercussions on agriculture, is one of the most important adaptation challenges for livestock production. Poultry production is a major source of proteins for human consumption all over the world. With a growing human population, improving poultry’s adaptation to environmental constraints becomes critical. Extensive evidence highlights the influence of environmental variations on epigenetic modifications. The aim of this paper is therefore to explore chickens’ molecular response to maternal heat stress. We employed Reduced Representation Bisulfite Sequencing (RRBS) to generate genome-wide single-base resolution DNA methylation profiling and RNA sequencing (RNA-seq) to profile the transcriptome of the brains of embryos hatched from dams reared under either heat stress (32 °C) or thermoneutrality (22°C). We detected 289 significant differentially methylated CpG sites (DMCs) and one differentially methylated region (DMR) between heat stressed and control groups. These DMCs were associated with 357 genes involved in processes such as cellular response to stimulus, developmental processes and immune function. In addition, we identified 11 genes differentially expressed between the two groups of embryos, and identified ATP9A as a target gene of maternal heat stress on offspring. This study provides a body of fundamental knowledge on adaptive mechanisms concerning heat tolerance in chickens