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A farmer-oriented method for co-designing groundwater-friendly farm management
No full textInternational audienceFrench and EU policies have been only partially successful in promoting the restoration of groundwater quality. The currently proposed measures are scientifically valid but ineffective in encouraging farmers to change their practices over the longer term. Participatory approaches have been developed for co-designing scenarios at cropping system or catchment area level, to improve groundwater quality. Farmers are one of several types of stakeholders who make contributions in this respect. In this context, we propose a similar participatory approach, although with two key differences: only farmers take part in the co-design process, and a farm-scale systemic perspective is applied. Our method, inspired by co-development, involves five steps, including groundwater quality pressure assessment. Within this method, we generate farmer-to-farmer suggestions aimed at improving farm management from an economic, social, and environmental perspective, with an emphasis on reducing pollution in catchments. The co-design groundwater-friendly farm management combines re-designed elements (e.g., changing agricultural practices or cropping systems or machinery or labor) that are consistent with the project specified by the farmer and that simultaneously decrease pressure on groundwater quality. We tested our method using two groups of farmers from southeastern France, located in areas concerned by groundwater quality issues related to nitrate and pesticide pollution. Our results show that our method based on farmer-to-farmer exchanges with a systemic approach constitutes an interesting and viable solution. In the months following the co-design process, the farmers in the test groups implemented some of the innovations suggested by their peers, thus creating a new groundwater-friendly farm management. This approach could be used in regions with other environmental challenges since the ultimate goal is to encourage sustainable farming practices. However, in the proposed methodology, the knowledge provided only by farmers might be too homogeneous, thus limiting the scope of changes in farming practices
Les méthodes visuelles d’évaluation de la structure du sol au service d’une démarche clinique en agronomie
No full textInternational audienceThe attention paid to soil structure is growing in relation to the evolution and diversification of tillage systems and the move towards to more agro-ecological systems. Visual methods have been widely used to evaluate and make a diagnosis of soil structure in field conditions. In this issue we review the main methods and look at their strengths and limitations. The methods are divided into two main groups according to the sampling methods: the methods based on the description of the vertical face of a soil profile and the "spade" methods based on the description of soil blocks extracted from the plot. The different methods use the same type of criteria to evaluate the soil structure: the analysis of the voids of the soil through an evaluation of the visible porosity visible and the organization of the solid fraction (shape, the size distribution, the degree of cohesion of clods, proportion of fine aggregates ... However how to evaluate the soil structure is very different between methods. The “profil cultural” method favours a spatial analysis of the soil structure to infer on its genesis whereas the "spade" methods assign an overall score to evaluate the soil structure quality. The review shows there are several reliable visual methods, but the differences in the way to evaluate soil structure and in the implementation of the methods mean that the choice of methods must be made according to the objectives pursued and the users.L’attention portée à la structure du sol connaît actuellement un regain d’intérêt, en relation avec l’évolution et la diversification des pratiques de travail du sol et la conception de systèmes de culture plus agro-écologiques. Les méthodes visuelles ont largement été utilisées pour évaluer et porter au champ un diagnostic sur la structure du sol. Dans ce numéro, nous passons en revue les principales méthodes et regardons leurs atouts et limites. Les méthodes se différencient en deux grands groupes suivant les modalités d’échantillonnage des volumes de sols observés : les méthodes basées sur la description de la face d’observation d’un profil de sol comme le profil cultural et les méthodes « bêche » basées sur la description de blocs de sol extraits de la parcelle. Elles utilisent toutes les mêmes types de critères pour observer l’état structural : l’analyse des vides du sol à travers une évaluation de la porosité visible à l’œil et l’organisation de la fraction solide (forme, distribution des tailles, le degré de cohésion des mottes, importance de la terre fine…). Cependant, la procédure d’évaluation de la structure est très différente suivant les méthodes. Le profil cultural privilégie une analyse spatiale de l’état structural pour inférer sur sa genèse alors que les méthodes « bêche » conduisent à une note globale de la qualité de la structure du sol. Cette revue montre que nous disposons de plusieurs méthodes fiables, qui peuvent être choisies en fonction des objectifs poursuivis et de leur plus ou moins grande facilité de mise en œuvre
Sustainable second-generation biofuel production potential in a developing country case study
No full textInternational audienceIran is the fourth biggest producer of crude oil and natural gas in the world. Meanwhile, this country is the largest CO2 emitter among the Middle East countries and 99% of energy in this country is produced from nonrenewable-based resources. Nevertheless, Iran has a promising potential to generate energy from its renewable resources such as biomass. Therefore, renewable energy generation can contribute to increasing the renewable energy share in the country’s energy generation and mitigating the environmental impacts. Thus, the aim of this research was to evaluate the second generation biofuel production potential in Guilan province (as one of the important agricultural areas in the region) of Iran. In this research, energy generation from cow manure, poultry manure, municipal solid wastes, rice wastes, and peanut wastes were studied. The results showed that the total energy generation from second-generation biomass resources in Guilan province of Iran was 76,523,985.50 GJ year−1. The yearly potential of energy generation from cow manure, poultry manure, municipal solid wastes, rice wastes, and peanut wastes were 2,284,529, 352,138, 648,523, 73,238,768, and 27 GJ, respectively. In conclusion, there is a remarkable potential to generate energy from second-generation biomass resources in Guilan province of Iran
État de l'art des techniques de génie végétal pour contrôler les renouées
No full text[Departement_IRSTEA]TerritoiresBased on the competitive effects of native plants, bioengineering technics aim both at controlling the development of Asian knotweeds and at restoring a diverse plant community in invaded areas. These methods are appealing to more and more managers. This article deals with such methods mobilizing herbaceous or ligneous species, associated sometimes with pre-treatments but always with accompanying measures. After a synthesis on the ecological mechanisms involved, some technics specifically used to manage Asian knotweeds are described with a focus on riparian habitats. Finally the conclusion raises the question of the importance to share experiences in order to progress in the implementation of bioengineering methods to control knotweeds.Basées sur l'utilisation des effets compétitifs des végétaux indigènes, les techniques de génie écologique visent à la fois le contrôle du développement des renouées asiatiques et la restauration d'une communauté végétale diversifiée dans les zones envahies. Ces méthodes alternatives intéressent de plus en plus de gestionnaires. Cet article s'intéresse ici à ces techniques, mobilisant des ligneux comme des herbacées, parfois associées à des prétraitements, mais obligatoirement à des mesures d'accompagnement. Après une synthèse des mécanismes écologiques sur lesquels elles reposent, une description de différentes méthodes est proposée, appliquées au cas des renouées asiatiques avec un focus particulier sur les milieux rivulaires. Enfin, la conclusion insiste sur la nécessité de partager et mutualiser les expériences afin de mieux comprendre les déterminants des succès et des échecs et avancer faire une meilleure mise en oeuvre de ces méthodes prometteuses
InnovAB - Améliorer les systèmes de grande culture en agriculture biologique : enseignements d’un réseau d’expérimentations de longue durée
No full textNational audiencePour 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
Functional diversity of cover crop mixtures enhances biomass yield and weed suppression in a Mediterranean agroecosystem
No full textInternational audienceFunctional diversity of cover crop mixtures is thought to improve biomass production and weed suppression, two key agroecosystem services in organic systems. To test this hypothesis, we selected eight cover crop species belonging to four functional groups: (i) vining growing large-seeded legumes (field pea, common vetch), (ii) erect growing small-seeded legumes (crimson clover, squarrosum clover), (iii) grasses (barley, oats) and (iv) Brassicaceae (radish, black mustard). Nine cover crop mixtures were designed to create a gradient of diversity in terms of number of species and number of functional groups. A control treatment and all monocrops were included in the trial. Regarding cover crop biomass, mixtures outyielded monocrops by an average of 37%. Both functional identity and composition (i.e. trait complementarity) influenced biomass production and weed suppression provided by cover crops. Regression analysis showed that increase in both species diversity and functional diversity in cover crop mixtures improved the provision of agroecosystem services. Results from this study show that complementarity of species functional traits in cover crop mixtures can be used as a strategy to ensure high biomass production and good weed suppression in changing agroecosystems
Wheat genotypic diversity and intercropping to control cereal aphids
No full textInternational audienceIncreasing intrafield plant diversity has been shown to regulate pest populations. Mixing wheat cultivars and intercropping winter wheat and white clover are both promising agroecological practices. On field experiments over two growing seasons, we combined both practices and examined the impact on aphid populations and on wheat production. Results show that combining intra- and interspecific diversity did not outperform each practice individually in reducing aphid populations. Taken separately, intercropping tended to have lower aphid infestation, while it was intermediate in cultivar mixtures. Yearly variation in climatic conditions impacted wheat and clover development, as well as the appearance of aphid peaks. Wheat yields and grain nitrogen content were reduced in intercropping by 10% and 7%, respectively, but not in cultivar mixtures. Our findings suggest that intrafield diversification may regulate wheat aphids to some extent, but combining two diversification practices did not result in an attractive trade-off between pest regulation and wheat production in real farming conditions
Spray-drying of protein/polysaccharide complexes: Dissociation of the effects of shearing and heating
No full textInternational audienceThe aim of this study was to dissociate the effect of atomization from that of heating during the spray-drying of Low Methoxyl (LM) pectin/sodium caseinate complexes. The properties of these complexes were studied by measuring turbidity, particle size distribution, zeta-potential, as well as surface hydrophobicity of caseinate within the formed complexes. The results showed that the spraying step had a significant effect on the charge and the size of the complexes. In fact, the application of atomization resulted in the dissociation of caseinate/ pectin aggregates especially for high pectin concentrations. Besides, the analysis of the surface hydrophobicity of caseinate indicated that complexation with high concentrations of pectin is able to protect the structure of the protein against heat denaturation. This study allowed a better understanding of the influence of atomization and heat treatment (during the dehydration step) on the molecular interactions within caseinate/pectin complexes
LEGITIMACY OF TERMINAL WHOLESALE MARKETS AS STAKEHOLDERS OF LOCAL FOOD CHAINS
No full textInternational audienceTerminal wholesale markets (TWM) aim at supplying consumption areas, especially urban areas. They are physical places where professional agents (producers, wholesalers, retailers, restaurant owners) meet to sell and buy wholesale food products. Since the late 1970s, French TWM have been facing increasing competition. More recently, in a context of change toward food re-localization, their legitimacy as intermediaries is also questioned. This article aims to analyze the strategies that French TWM implement in order to re-legitimate themselves as stakeholders of more local and sustainable food systems. We focus on two cases in Auvergne-Rhône-Alpes Region, the Lyon-Corbas private market and Grenoble « Market of national interest ». The purpose is to assess their 'hybridity', between 'alternative' and 'conventional', how this may restore their legitimacy and allow them to maintain their activity
Dispersion par les cours d’eau des propagules végétatives et sexuées du complexe d’espèces Reynoutria
No full textInternational audienceChez les renouées asiatiques (complexe Reynoutria), l’eau des rivières est un des principaux vecteurs naturels de dispersion des propagules sexuées (akènes ailés) et végétatives (fragments de tiges et de rhizomes). Les auteurs de cet article ont étudié la flottaison et la viabilité de ces trois types de propagules en conditions expérimentales pour différentes taches de renouées. De leurs études, il en ressort une grande variabilité entre les taches pour un grand nombre de traits impliqués dans la dispersion par le cours d’eau et la colonisation des berges