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Calibration and Evaluation of the STICS Intercrop Model for Two Cereal-Legume Mixtures
No full textIntroduction
STICS is a soil-crop model capable of simulating crops in succession (Brisson et al., 2003).
Intercropping occurs when multiple species are grown simultaneously on the same field. There has
been a growing interest in adapting this traditional technique for modern agriculture as a way of
ecological intensification, especially for combining leguminous and cereal crops in order to reduce N
inputs and potential environmental damage through N losses. Intercropping adds complexity to the
system by adding inter-species competition. Crop models are useful tools for analyzing complex
systems, as they allow the user far more control over individual variables than is possible in field
experiments. A first version of the STICS intercrop model was created by Brisson et al. (2004) and
was recently improved by Vezy et al. (2020). The aim of this study was to calibrate and evaluate this
improved STICS-Intercrop model by simulating a winter and a spring intercrop mixture: durum
wheat-winter pea and barley-spring pea.
Materials and Methods: [br/]The data set used for modelling comprised of four years of wheat (Triticum turgidum L.) and pea (Pisum sativum L.) field data from Auzeville, France with multiple levels of nitrogen fertilizer, and four years of barley (Hordeum vulgare L.) and pea field data from Angers, France (Corre-Hellou, 2005), which in
some years included two levels of nitrogen fertilizer and two different plant densities of the intercrops.
The sole crop trials were used for calibration and the intercrop trials for evaluation, except for a subset
of intercrop data that was used to calibrate the parameters unique to the intercrop model. The
assumption was that parameters common to both sole and intercropping, such as plant-soil
interactions and phenology, would be the same for both. The optimization method used for calibration
was based on Wallach et al. (2011). The parameters were broken down into 15 groups (16 for pea
including nitrogen fixation) for calibration, each corresponding to a different process.
Results and Discussion: The model calibration process is still ongoing. The root mean square error (RMSE) for shoot biomass was 1.92 t/ha for winter pea and 1.37 t/ha for durum wheat. The RMSE for grain yield was 1.84 t/ha for spring pea and 1.15 t/ha for barley. Overall the model captured the dominancy of one species
quite well, however the accuracy has to be increased. The phenology and height were correctly
simulated. Some of the discrepancies could be due to biological stresses that STICS does not capture.
Some parameters for the pea-wheat model have not been calibrated yet, so the RMSE is likely to
improve. Conclusions: Intercrop systems are difficult to model in comparison to sole crops due to their complex
interactions, but the STICS model, after having completed the calibration, could be a useful tool for
better understanding the biological functions of this management practice
Improvement of genomic prediction by integrating additional single nucleotide polymorphisms selected from imputed whole genome sequencing data.
No full textThe availability of whole genome sequencing (WGS) data enables the discovery of causative single nucleotide polymorphisms (SNPs) or SNPs in high linkage disequilibrium with causative SNPs. This study investigated effects of integrating SNPs selected from imputed WGS data into the data of 54K chip on genomic prediction in Danish Jersey. The WGS SNPs, mainly including peaks of quantitative trait loci, structure variants, regulatory regions of genes, and SNPs within genes with strong effects predicted with variant effect predictor, were selected in previous analyses for dairy breeds in Denmark-Finland-Sweden (DFS) and France (FRA). Animals genotyped with 54K chip, standard LD chip, and customized LD chip which covered selected WGS SNPs and SNPs in the standard LD chip, were imputed to 54K together with DFS and FRA SNPs. Genomic best linear unbiased prediction (GBLUP) and Bayesian four-distribution mixture models considering 54K and selected WGS SNPs as one (a one-component model) or two separate genetic components (a two-component model) were used to predict breeding values. For milk production traits and mastitis, both DFS (0.025) and FRA (0.029) sets of additional WGS SNPs improved reliabilities, and inclusions of all selected WGS SNPs generally achieved highest improvements of reliabilities (0.034). A Bayesian four-distribution model yielded higher reliabilities than a GBLUP model for milk and protein, but extra gains in reliabilities from using selected WGS SNPs were smaller for a Bayesian four-distribution model than a GBLUP model. Generally, no significant difference was observed between one-component and two-component models, except for using GBLUP models for milk
Critical review of the role of PPE in the prevention of risks related to agricultural pesticide use
No full textPersonal protection equipment (PPE) holds a privileged position in safety interventions in many countries, despite the fact that they should only be used as a last resort. This is even more paradoxical because many concerns have arisen as to their actual effectiveness under working conditions and their ability to provide the protection attributed to them by certain occupational safety strategies and marketing authorisation procedures. Are these concerns justified? This article is intended to provide an update on what we know of the issue based on a critical analysis of the literature to date. Analysis focuses on the assessment of the effectiveness of coveralls used to protect from plant protection products in OECD countries. All forms of assessment were retained: discussion of the observed effectiveness of PPE in relation to the underlying assumptions of marketing authorisation procedures, laboratory tests of equipment, practical field tests in which PPE-wearing practices were controlled and uncontrolled, analyses of the efficiency of preventive instructions based on wearing such coveralls. Findings show that recommending the use of PPE is key to the granting of marketing authorisation. Some dangerous products only get marketing authorisation because it is assumed that wearing PPE will considerably limit exposure. They would be banned if it were not for this assumption of protection. However the actual effectiveness of PPE in working conditions may be over-estimated. In addition many factors (cost, availability, thermic and mechanical discomfort) may make instructions to wear PPE inapplicable. Advising the use of PPE does not always mean effective protection
Data on winged insect dynamics in melon crops in southeastern France
No full textThis article displays insect count data obtained in eleven field trials conducted between 2010 and 2019 in southeastern France. Winged insect abundances were monitored daily within melon crops during 8 to 11 weeks in May-July using a suction trap or a yellow pan trap. Aphids were identified under a stereomicroscope. In total, 29,709 winged aphids belonging to 216 taxa and 151,061 other flying insects were caught. Among possible uses, these data can populate larger multisite studies or larger time series investigating aphid community variations. They can also feed generic studies exploring temporal dependencies or species assemblages. They can stimulate new collaborations with entomologists keen on implementing molecular tools or taxonomic expertise on a large specimen collection
Synthetic Biology Applied to Carbon Conservative and Carbon Dioxide Recycling Pathways
No full textThe global warming conjugated with our reliance to petrol derived processes and products have raised strong concern about the future of our planet, asking urgently to find sustainable substitute solutions to decrease this reliance and annihilate this climate change mainly due to excess of CO2 emission. In this regard, the exploitation of microorganisms as microbial cell factories able to convert non-edible but renewable carbon sources into biofuels and commodity chemicals appears as an attractive solution. However, there is still a long way to go to make this solution economically viable and to introduce the use of microorganisms as one of the motor of the forthcoming bio-based economy. In this review, we address a scientific issue that must be challenged in order to improve the value of microbial organisms as cell factories. This issue is related to the capability of microbial systems to optimize carbon conservation during their metabolic processes. This initiative, which can be addressed nowadays using the advances in Synthetic Biology, should lead to an increase in products yield per carbon assimilated which is a key performance indice in biotechnological processes, as well as to indirectly contribute to a reduction of CO2 emission
Un protocole pour une enquête par questionnaire anonyme au sens du Règlement européen
No full textL’entrée en vigueur du Règlement général sur la protection des données personnelles (RGPD) dans l’Union européenne en 2018 a conduit de nombreux sociologues à s’interroger sur la concordance entre leurs pratiques d’enquêtes et le cadre législatif. Enseigner comment faire une enquête par questionnaire implique de former les étudiants à ces aspects déontologiques et juridiques des pratiques d’enquête. Aussi je me suis faite accompagnée par une juriste déléguée à la protection des données pour vérifier que la petite enquête par questionnaire (10 minutes) que je faisais réaliser chaque année par mes étudiants de master était conforme à la législation. Ce travail a débouché sur un protocole pour une enquête anonyme (par téléphone et auto-administré sur internet) qui est reproduit ici. Il est précédé d’une mise en contexte sur la législation sur les données personnelles ; sur la façon dont se déroule l’enquête pour laquelle j’ai conçu ce protocole ; enfin sur le choix d’anonymiser complètement l’enquête.
Un protocole pour une enquête par questionnaire anonym
Verger Cidricole de Demain : les enseignements après 6 ans d’expérimentation système pour réduire les intrants en jeunes vergers cidricoles
No full textDurant 6 ans, le programme Verger Cidricole de Demain a expérimenté 9 vergers de pommiers à cidre bas-intrants « ECO », implantés chez 9 cidriculteurs du Nord-Ouest de la France. En comparaison à 9 vergers témoin « PROD », le projet visait à évaluer la faisabilité technique et les performances économiques, environnementales, sociales et agronomiques de ces vergers prototypes, où des pratiques culturales ont été combinées dans une approche dite « système ». Grâce à l’enregistrement de près de 40 000 données, des références technico-économiques ont été acquises sur les moyens permettant de réduire les intrants en jeune verger, notamment l’emploi des produits phytosanitaires. Les 9 systèmes « ECO » ont atteint une réduction moyenne des IFT hors biocontrôle de 48%. Combinées aux changements de pratiques de fertilisation et de couverture sur l’inter-rang (implantation de bandes fleuries), les méthodes alternatives au désherbage chimique du rang testées semblent davantage pénaliser l’entrée en production des systèmes « ECO » que la réduction des fongicides et des insecticides. En revanche, les stratégies alternatives testées contre la tavelure ont permis de réduire significativement les IFT fongicides sans conséquence pour la production des vergers « ECO ». Des itinéraires techniques viables à plus bas intrants restent donc possibles en verger cidricole à conditions d’optimiser certains leviers et leur combinaison, parmi lesquels : la génétique (résistance variétale et porte-greffes adaptés), la prophylaxie, le biocontrôle, l’efficience (outils d’aide à la décision et seuils d’intervention), la protection physique (bâche tissée ou mulch de copeaux de bois sur le rang associé à une fertilisation optimale), la lutte biologique (par conservation via l’implantation de bandes fleuries).The “Verger Cidricole de Demain” (literally: Cider Apple Orchards of the Future) research project had experimented for 6 years with 9 low-input cider apple orchards named “ECO”. These were established under field conditions in 9 cider growers spread out in the north-west of France. With regard to 9 cider apple orchard references named “PROD”, the project aimed at assessing the technical feasibility and the economic, environmental, social and agronomic performances of these orchard prototypes, where cultural practices had been combined in a systemic approach. Thanks to the record of about 40,000 data points, technical and economic references had been acquired to reduce inputs in young cider apple orchards, such as the use of pesticides. The 9 ECO systems reached an average reduction of the chemical treatment frequency index (in French: IFT) of 48 % with regard to the PROD reference. When combined with changes in fertilization and plantation of flower strips in the orchard inter-rows, the alternatives to herbicide use in weed management seem to be more penalizing on the first fruiting than the reduction of fungicides and insecticides. However, thanks to the tested alternative strategies to fight apple scab, fungicide treatment frequency index was significantly reduced without impacting the yields of the ECO orchards. Viable low-input farming practices remain possible in cider apple orchards if some technics and their combinations are optimised. Among these are: genetics (varietal resistance and adapted rootstocks), prophylaxis, biocontrol products, efficiency (models and decision thresholds), physical protections (inert mulches on the tree rows for weed management, such as wood chip mulch or weed fabric, associated with an optimal fertilization), beneficial insects (by preservation with plantation of flower strips)
A spatially explicit database of wind disturbances in European forests over the period 2000-2018
No full textStrong winds may uproot and break trees and represent a major natural disturbance for European forests. Wind disturbances have intensified over the last decades globally and are expected to further rise in view of the effects of climate change. Despite the importance of such natural disturbances, there are currently no spatially explicit databases of wind-related impact at a pan-European scale. Here, we present a new database of wind disturbances in European forests (FORWIND). FORWIND is comprised of more than 80 000 spatially delineated areas in Europe that were disturbed by wind in the period 2000-2018 and describes them in a harmonized and consistent geographical vector format. The database includes all major windstorms that occurred over the observational period (e.g. Gudrun, Kyrill, Klaus, Xynthia and Vaia) and represents approximately 30% of the reported damaging wind events in Europe. Correlation analyses between the areas in FORWIND and land cover changes retrieved from the Landsat-based Global Forest Change dataset and the MODIS Global Disturbance Index corroborate the robustness of FORWIND. Spearman rank coefficients range between 0.27 and 0.48 (p value < 0.05). When recorded forest areas are rescaled based on their damage degree, correlation increases to 0.54. Wind-damaged growing stock volumes reported in national inventories (FORESTORM dataset) are generally higher than analogous metrics provided by FORWIND in combination with satellite-based biomass and country-scale statistics of growing stock volume. The potential of FORWIND is explored for a range of challenging topics and scientific fields, including scaling relations of wind damage, forest vulnerability modelling, remote sensing monitoring of forest disturbance, representation of uprooting and breakage of trees in large-scale land surface models, and hydrogeological risks following wind damage. Overall, FORWIND represents an essential and open-access spatial source that can be used to improve the understanding, detection and prediction of wind disturbances and the consequent impacts on forest ecosystems and the land-atmosphere system. Data sharing is encouraged in order to continuously update and improve FORWIND
