Le projet Agro-éco-Syst’Nvisait à doter les conseillers agricoles, formateurs et enseignants de méthodes, outils et références leur permettant d’identifier et de concevoir des systèmes de culture à ...faibles pertes azotées vers l’environnement. A cette fin, une méthode de diagnostic des pertes d’azote vers l’eau (par lixiviation) et vers l’air (par volatilisation), utilisant l’outil Syst’N®, a été élaborée et formalisée. Elle a ensuite été utilisée pour évaluer et expliquer les performances azotées de plusieurs systèmes de culture dans des contextes pédoclimatiques variés.Quinze systèmes de culture ont ainsi été évalués et diagnostiqués. Leur analyse transversale a montré comment différentes combinaisons de pratiques dans un contexte donné conduisent à des performances variables en matière de pertes d’azote. Enfin, 21 cas-types ont été mis à disposition pour outiller les enseignants et conseillers sur le diagnostic des pertes d’azote, ressources mobilisables dans un éventail d’objectifs pédagogiques, de l’évaluation des pertes azotées à la reconception de systèmes de culture. Les systèmes simulés avec Syst’N®sont diffusés viala base de données Pertazote, mise à niveau au cours du projet
Pour accompagner l’essor actuel de l’agriculture biologique, il est important de disposer de référencessur la conception de systèmes de culture durables, pour des agriculteurs récemment convertis ou ...plusexpérimentés. L’évaluation faite de systèmes de grande culture bio innovants, testés en réseaud’expérimentations système de longue durée, montre de bonnes contributions au développementdurable, avec des performances économiques et environnementales satisfaisantes. Des points devigilance ressortent sur le maintien à long terme du potentiel de production des parcelles (risques dedéveloppement non contrôlé d’adventices, de carences en éléments minéraux). Les systèmesprivilégiant la mobilisation de leviers agro-écologiques montrent des perspectives intéressantes.
The use of the ecosystem service notion by natural scientists is increasing since the Millenium Ecosystem Assessment report publication in 2005. This notion is generally associated with an economic ...assessment of the services that nature brings to humans, and thus it implies new relationships between science and public policy. It also questions the nature of scientific knowledge, since this knowledge must contribute more directly to the building of environmental policies. This article is focused on agricultural soils ; its aim is to study the ecosystem service approach impact on scientific production in soil science. A bibliographic study with the lexicometric software Iramuteq was made. Corpuses of scientific articles published from 1992 to 2012 were set up with the database Web of Science and they were analysed with Iramuteq. The results of the different corpus analysis were compared. So we observed that since the nineties, there have been important changes in research themes and relations between scientific disciplines within soil sciences. The main tendency in the study of agricultural soils is the expansion of ecological approaches. Articles which mention ecosystem service notion have distinctive characteristics : (i) modelling methods are not much used ; (ii) farming practices studies focus on their effects on soil conservation rather than on soil productivity and food production ; (iii) biological and ecological approaches are diversified and focused on micro- and macro-organisms communities and activities. Moreover, in the scientific literature we analyzed, ecological and biochemical processes that take place in agricultural soils are more and more precisely studied, but they are not linked with the provision of ecosystem services. As a conclusion, presently, the use of ecosystem service notion by researchers doesn’t change the knowledge nature produced on agricultural soils.
Depuis la publication du rapport du Millenium Ecosystem Assessment (2005), on observe une utilisation croissante de la notion de service écosystémique (SE) par les chercheurs des sciences de la nature. Or cette notion, qui est généralement associée à une évaluation économique des services rendus à la nature par l'homme, renouvelle les relations entre science et politique. Elle réinterroge la nature des connaissances scientifiques, celles-ci devant contribuer plus directement à la définition des politiques de protection de l'environnement. Dans cet article, nous nous sommes plus particulièrement intéressés aux sols agricoles, pour étudier en quoi l'approche par service écosystémique conduit à modifier la production scientifique sur cet objet. Pour ce faire, nous avons réalisé une étude bibliographique approfondie à l'aide du logiciel de lexicométrie Iramuteq. Nous avons analysé plusieurs corpus d'articles scientifiques de sciences du sol publiés entre 1992 et 2012 et sélectionnés sous la base de données Web of Science, puis nous avons comparé les résultats de ces analyses. Nous avons ainsi mis en évidence une évolution forte des thématiques et des relations entre disciplines au sein des sciences du sol depuis les années 1990, avec principalement une montée des approches écologiques dans l'étude des sols agricoles. Nous avons également montré que les articles qui font référence à la notion de SE présentent des spécificités : (i) la modélisation n'apparaît pas comme une méthode centrale d'étude ; (ii) les pratiques agricoles sont appréhendées sous l'angle de la préservation des sols plutôt que de leur exploitation à des fins de production ; (iii) les approches biologiques et écologiques sont diversifiées et centrées davantage sur les communautés et les activités des organismes vivants. Par ailleurs, dans la littérature scientifique analysée, l'étude de processus écologiques et biogéochimiques donnés qui prennent place dans les sols agricoles est privilégiée mais elle n'est pas reliée de manière précise aux services qu'ils sont susceptibles de fournir. Par conséquent, pour l'heure, l'utilisation par les chercheurs en sciences du sol de la notion de SE n'entraîne pas de changements majeurs concernant la nature des connaissances qu'ils produisent sur les sols utilisés par l'agriculture.
Depuis quelques décennies, le labour, comme mode de travail du sol, tend à diminuer au profit de différents modes de préparation du sol, allant du travail du sol réduit sans retournement jusqu'au ...semis direct. De tels modes alternatifs de travail du sol méritent une étude approfondie avant leur diffusion en agriculture biologique (AB) car ils peuvent occasionner des problèmes de nutrition des cultures et une dégradation de la structure du sol au cours des premières années de leur application. L'objectif de ce travail a donc été d'étudier à court terme (< 5 ans) les modifications que génèrent l'adoption de différentes techniques de travail du sol en AB sur la structure du sol, la répartition des résidus de culture et des microorganismes au sein du profil cultural, puis d'en évaluer les conséquences sur la minéralisation potentielle du carbone et de l'azote. Pour cela, le travail s'est appuyé sur deux dispositifs agronomiques mis en place l'un sur sol alluvial sableux (Lyon), l'autre sur sol limoneux de Bretagne (Kerguéhennec) pour comparer les effets de quatre modes de travail du sol : labour traditionnel, labour "agronomique", travail réduit et superficiel. Dans chacun de ces sites, des prélèvements ont été réalisés à partir de l'observation des profils culturaux au sein de zones compactées (mottes delta) et non compactées (mottes gamma) à différentes profondeurs correspondant aux limites de travail des outils étudiés. Cette stratégie d'échantillonnage a permis de relier la structure du sol au fonctionnement microbien et de mieux comprendre les facteurs qui gouvernent l'organisation spatiale des microorganismes à une échelle macroscopique et ce, aussi bien d'un point de vue quantitatif (biomasse microbienne, activités de minéralisation) que qualitatif (structure des communautés microbiennes). Ainsi, dès les premières années de différenciation des traitements, la quantité, l'activité mais aussi la structure des communautés microbiennes sont influencées par la profondeur et le mode d'enfouissement des résidus puis, dans les horizons où la quantité de substrat disponible n'est pas limitante, par le tassement du sol généré par chaque technique. La prise en compte de l'hétérogénéité spatiale de la structure du sol permet de préciser l'effet de chaque technique étudiée sur le potentiel de minéralisation du carbone et d'azote des microorganismes. Ainsi, dans les conditions expérimentales de ce travail, il apparaît que l'adoption de techniques de travail du sol réduit ou superficiel ne limite pas le potentiel d'azote minéralisable total (sur l'ensemble de la couche de sol) par rapport au labour au cours des premières années de leur application.
Organic agriculture is a production system which relies on ecosystem management and ecological processes rather than on the external flow of agricultural inputs. The development of the organic sector ...has incluced a spatial decoupling of livestock and crop production. This has increased the flow of nutrients that occurs between farms compared to what happens within individual farms. Organic systems have replaced synthetic inputs with site-specific management practices to balance input and output nutrients to ensure short-term productivity and long-term sustainability. This paper addresses the nutrient management of mixed and specialized farming systems, with a special emphasis on the reliance on livestock production for the nutrient management of arable farmland. We assessed the nutrient budgets of nitrogen (N), phosphorus (P), and potassium (K) of 28 organic farms selected according to livestock density from three French countries. The farms were classified as stockless, mixed, and cattle farming systems. A soil surface nutrient budget was calculated for each farm based on inputs (N fixation, excreta, and manure) and outputs (grazing, offtake, harvests) on annual crops and grasslands. Inputs due to N atmospheric deposition and seeds and losses due to leaching and volatization were not considered in this study. Nutrient budgets of the 28 farms revealed N, P and K deficits, although disparities between farming systems and their geographical location were also observed. Stockless farms presented high N deficit whereas mixed and livestock farming systems presented lower deficits (close to equilibrium) or even surpluses in a county with a high density of livestock farms. Differences between farming systems in terms of P and K budgets followed the same trend, but regional specificities appreared significant in stockless and livestock systems (related to the size of farms and the stocking rate). None of the farms purchased off-farm organic fertilizers when exchanges of manures and straw were observed at the regional scale. When livestock is present on the farm, the nutrient resources came mainly from recycling internal resources (manures, excreta, and N fixation), whereas stockless farming systems purchased organic manure from neighboring farms ( 14 to 58 % of total N inputs, 10 to 100 % of total P and K inputs). The sustainability of stockless organic farming systems is questioned, noticeably those that were located in regions where resources of organic matter are scarce. Only farming systems producing large quantities of manure or which purchased feed showed balanced nutrient budgets.
Organic agriculture is a production system which relies on ecosystem management and ecological processes rather than on the external flow of agricultural inputs. The development of the organic sector ...has incluced a spatial decoupling of livestock and crop production. This has increased the flow of nutrients that occurs between farms compared to what happens within individual farms. Organic systems have replaced synthetic inputs with site-specific management practices to balance input and output nutrients to ensure short-term productivity and long-term sustainability. This paper addresses the nutrient management of mixed and specialized farming systems, with a special emphasis on the reliance on livestock production for the nutrient management of arable farmland. We assessed the nutrient budgets of nitrogen (N), phosphorus (P), and potassium (K) of 28 organic farms selected according to livestock density from three French countries. The farms were classified as stockless, mixed, and cattle farming systems. A soil surface nutrient budget was calculated for each farm based on inputs (N fixation, excreta, and manure) and outputs (grazing, offtake, harvests) on annual crops and grasslands. Inputs due to N atmospheric deposition and seeds and losses due to leaching and volatization were not considered in this study. Nutrient budgets of the 28 farms revealed N, P and K deficits, although disparities between farming systems and their geographical location were also observed. Stockless farms presented high N deficit whereas mixed and livestock farming systems presented lower deficits (close to equilibrium) or even surpluses in a county with a high density of livestock farms. Differences between farming systems in terms of P and K budgets followed the same trend, but regional specificities appreared significant in stockless and livestock systems (related to the size of farms and the stocking rate). None of the farms purchased off-farm organic fertilizers when exchanges of manures and straw were observed at the regional scale. When livestock is present on the farm, the nutrient resources came mainly from recycling internal resources (manures, excreta, and N fixation), whereas stockless farming systems purchased organic manure from neighboring farms ( 14 to 58 % of total N inputs, 10 to 100 % of total P and K inputs). The sustainability of stockless organic farming systems is questioned, noticeably those that were located in regions where resources of organic matter are scarce. Only farming systems producing large quantities of manure or which purchased feed showed balanced nutrient budgets.
Summary Background Spinal muscular atrophy (SMA) is a progressive motor neuron disease causing loss of motor function and reduced life expectancy, for which limited treatment is available. We ...investigated the safety and efficacy of olesoxime in patients with type 2 or non-ambulatory type 3 SMA. Methods This randomised, double-blind, placebo-controlled, phase 2 study was done in 22 neuromuscular care centres in Belgium, France, Germany, Italy, Netherlands, Poland, and the UK. Safety and efficacy of olesoxime were assessed in patients aged 3–25 years with genetically confirmed type 2 or non-ambulatory type 3 SMA. A centralised, computerised randomisation process allocated patients (2:1 with stratification by SMA type and centre) to receive olesoxime (10 mg/kg per day) in an oral liquid suspension or placebo for 24 months. Patients, investigators assessing outcomes, and sponsor study personnel were masked to treatment assignment. The primary outcome measure was change from baseline compared with 24 months between the two treatment groups in functional domains 1 and 2 of the Motor Function Measure (MFM D1 + D2) assessed in the full analysis population. A shorter, 20-item version of the MFM, which was specifically adapted for young children, was used to assess patients younger than 6 years. Safety was assessed in the intention-to-treat population. The trial is registered with ClinicalTrials.gov , number NCT01302600. Findings The trial was done between Nov 18, 2010, and Oct 9, 2013. Of 198 patients screened, 165 were randomly assigned to olesoxime (n=108) or placebo (n=57). Five patients in the olesoxime group were not included in the primary outcome analysis because of an absence of post-baseline assessments. The change from baseline to month 24 on the primary outcome measure was 0·18 for olesoxime and −1·82 for placebo (treatment difference 2·00 points, 96% CI −0·25 to 4·25, p=0·0676). Olesoxime seemed to be safe and generally well tolerated, with an adverse event profile similar to placebo. The most frequent adverse events in the olesoxime group were pyrexia (n=34), cough (n=32), nasopharyngitis (n=25), and vomiting (n=25). There were two patient deaths (one in each group), but these were not deemed to be related to the study treatment. Interpretation Olesoxime was safe at the doses studied, for the duration of the trial. Although the primary endpoint was not met, secondary endpoints and sensitivity analyses suggest that olesoxime might maintain motor function in patients with type 2 or type 3 SMA over a period of 24 months. Based on these results, olesoxime might provide meaningful clinical benefits for patients with SMA and, given its mode of action, might be used in combination with other drugs targeting other mechanisms of disease, although additional evidence is needed. Funding AFM Téléthon and Trophos SA.
This project aims at validating soil biological and agronomical indicators, as well as the transfer and training procedure to initiate an agricultural innovation network, and to monitor the impact of ...agricultural practices on soil biological life. The strategy used was based on selecting existing bioindicators, easily operational to be applied to a network of farming systems, in order to evaluate the environmental and agronomical impacts of agricultural practices. These bioindicators target three large groups of soil organisms, namely the earthworms, the nematodes, and the microbial communities. At the same time, agronomical indicators based on physico-chemical parameters, soil structure and organic matter decomposition were also used to better interpret the bioindicators. More than 230 private farms form the network (with an equal proportion of grapevine and arable farms), which therefore integrates a great variability of pedoclimatic and agricultural situations at the scale of the French territory. After a training on soil biology, soil observations and sampling, all these farmers sampled soil for laboratory measurements and characterized their soil structure and earthworms density. This project enables to test the feasibility of monitoring soil bioindicators for farmers, their operability and their utility for end-users. One of the main deliverable of the project was to elaborate a handbook which could allow the farmers to understand the impact of their agricultural practices on the soil biological life, and therefore to evaluate the sustainability of their production system by mobilizing laboratory and field indicators. From this project, a new sector of analyses and agronomic advice based on biological indicators is raising, following the need expressed by farmers.
This project aims at validating soil biological and agronomical indicators, as well as the transfer and training procedure to initiate an agricultural innovation network, and to monitor the impact of ...agricultural practices on soil biological life. The strategy used was based on selecting existing bioindicators, easily operational to be applied to a network of farming systems, in order to evaluate the environmental and agronomical impacts of agricultural practices. These bioindicators target three large groups of soil organisms, namely the earthworms, the nematodes, and the microbial communities. At the same time, agronomical indicators based on physico-chemical parameters, soil structure and organic matter decomposition were also used to better interpret the bioindicators. More than 230 private farms form the network (with an equal proportion of grapevine and arable farms), which therefore integrates a great variability of pedoclimatic and agricultural situations at the scale of the French territory. After a training on soil biology, soil observations and sampling, all these farmers sampled soil for laboratory measurements and characterized their soil structure and earthworms density. This project enables to test the feasibility of monitoring soil bioindicators for farmers, their operability and their utility for end-users. One of the main deliverable of the project was to elaborate a handbook which could allow the farmers to understand the impact of their agricultural practices on the soil biological life, and therefore to evaluate the sustainability of their production system by mobilizing laboratory and field indicators. From this project, a new sector of analyses and agronomic advice based on biological indicators is raising, following the need expressed by farmers.
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