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La mécanisation de la transformation de la banane plantain en Côte d'Ivoire : rapport d'enquêtes et analyses
Get PDFGeneral conclusion and perspectives [Remote sensing and spatial modelling. Applications to the surveillance and control of mosquito-borne diseases]
Get PDFSimulating biomass chains for agricultural and bioeconomy transitions: The agent-based model, BioChains
Get PDFThe agent-based model BioChains aimed at modelling and simulating the biomass flows between production and processing plants to support the design of sustainable territorial bioeconomic systems (Wohlfahrt et al. 2019). Starting from concepts and formalisms of the existing UPUTUC model (Soulié et al. 2017), biomasses are represented as ” pools ”, defined by their volume and type, transiting through multiple production, processing and consumption ”units”. In addition to their type (e.g: Faba beans, corn silage, pig slurry etc), each biomass pool is characterised by its age and physical characteristics (e.g.: dry matter, nitrogen content, phosphorus content etc), which may vary on a daily basis, due to phenomena such as degradation within storage units. BioChains has been designed to represent five layers of phenomena regarding the prospects of biomass pools in a territory; - Wells and sources of biomass: where are produced and consumed biomass pools? And at which rate? - Storage: what are the maximum capacities and storage conditions offered by the units of the territory? How do the physical characteristics of biomass pools change between the time they are stored and the time they are retrieved? - Transportation: how are biomass pools moved from one unit to another? How can ex- changes between units be assured, depending on the characteristics of freight companies' fleets? - Processing of biomass: What biomass pools are needed and processed by biomass processing plants of the territory? - Performances: how much greenhouse gases are emitted by composting or degradation during storage of a given quantity of biomass? How much bioproducts (e.g.: biogas, biomaterials) are produced through the different processing plants? How the transportation traffic in increase due to the development of the bioeconomy? BioChains allows integrating multiple coarse- or fine-grained bioprocess models. The bio- processes currently implemented are anaerobic digestion (through the SysMetha model) and household composting. An industrial composting platform model and a bioplastic production plant model are also underway. In a more general manner, the BioChains model has been designed as a framework into which new bioprocesses can easily be described and communicate between each other through generic interfaces. The BioChains module provide its users with building blocks allowing to model and simulate multiple scenarios of biomass chain organisations, like linear vs. cascading and circular ones, thus making it possible to assess their respective environmental and economic performances. Being powered by the GAMA platform, the BioChains module is designed to be pluggable into the MAELIA platform (Misslin et al., 2021) to simulate interactions between agricultural, hydrological and biomass pools dynamics. BioChains is capable to interact with MAELIA agents as well as to function as a "standalone" model. This coupling possibility adds the ability to test bioeconomy scenarios to MAELIA's Integrated Assessment Modelling approach (for example; which feasibility for a specific transformation unit layout on a territory? What scaling for the logistics around the upcycling of a given organic waste product?)
Beyond averages: Machine-learning unveil drivers of SOC changes under agroforestry in Latin America and the Caribbean
No full textIdée reçue n° 1 : L'agroécologie menace la production alimentaire mondiale
Get PDFLes différences de rendement de production entre systèmes agroécologiques et conventionnels varient en fonction des cultures, des zones géographiques et des pratiques agricoles. L'agriculture biologique, la forme la mieux étudiée d'agroécologie, présente une productivité à l'hectare moindre que l'agriculture conventionnelle. Ces différences de productivité peuvent s'expliquer par un manque de nutriments et des dommages causés aux cultures par les bioagresseurs et peuvent être limitées si l'on déploie des pratiques agronomiques adaptées. Ces différences de productivité doivent être relativisées car : - La productivité surfacique de l'agriculture conventionnelle va probablement diminuer avec la raréfaction des ressources ; - Une réduction de la consommation de produits animaux libérerait des surfaces pour des cultures directement destinées à l'alimentation humaine, compensant les pertes de productivité surfacique liées à l'agroécologie dans certaines filières ; Le développement de l'agroécologie va permettre d'améliorer ses rendements (recherche, renforcement des services apportés par les écosystèmes…)
Modelling the climate change adaptation potential of no-tillage maize systems in southern Africa
Get PDFSouthern Africa is a hotspot of climate change where smallholder farmers are particularly threatened because they largely depend on rainfed agriculture for their livelihoods. The objective of the study was to assess the potential of two main principles (no-tillage and crop residue retention) of conservation agriculture (CA) and nitrogen (N) fertilizer management to mitigate the negative effects of future climate (2021–2060) on maize (Zea mays L.) productivity using the Agricultural Production Systems Simulator (APSIM). Two tillage practices were considered in the simulations, i.e. the conventional practice of tillage with removal of crop residues (CP) and NT (no-tillage and crop residue mulching), as well as three rates of N input (0, 30, 90 kg ha−1) on mono-cropped continuous maize. Simulations were run for future climate generated by an ensemble of 17 global circulation models (GCMs) using two extreme emission scenarios based on Representative Concentration Pathways (RCP2.6 and RCP8.5) for southern Africa. Results from the simulations suggest that NT management is not more beneficial in the future (2051–2060) than in the current climate, and there is no evidence to support its ability to mitigate the climate change impacts at the study sites, because the effects are principally exerted through increased temperatures. Simulations further show that increased fertilizer N inputs could drastically increase maize productivity, but with increased vulnerability to climate change. Improved crop management practices such a NT need to be combined with improved crop genotypes tolerant to multiple stresses such as drought and heat to maximize resilience under future climatic conditions
Vers une transhumance apaisée à la frontière entre le Togo et le Burkina Faso ? Approche territoriale et anticipatrice
Get PDFUnderstanding stakeholder relationships and local context to build a community-based one health surveillance system in Guinea
Get PDFIn 2014, the Ebola virus epidemic that began in Guinea spread to several countries in sub-Saharan Africa, causing the deaths of almost 11,000 people. This crisis, caused in part by increased human contact with wildlife, was exacerbated by the lack of preparedness within the health sector of the affected countries, including inadequate surveillance of disease emergence from wildlife. Given that local communities face the greatest exposure to these issues, this study sought to acquire the contextual knowledge needed to set up community-based zoonotic disease surveillance. Field investigations based on a One Health approach were carried out at two sites in the Guéckédou prefecture in Guinea's forest region. Semi-structured individual interviews and focus group discussions were held with 87 members of the community. These interviews provided new information about zoonotic disease surveillance in Guinea, which we then used to map the health actors and their relationships within the community. We gathered details about the barriers they face and their concerns, such as the fundamental importance of training, a lack of legitimacy, and the differences in means allocated among the human, animal, environmental, health sectors. Some relatively unidentified stakeholders also emerged as possible communication channels. This study shows the importance of talking to the primary users of surveillance to ensure the acceptability and relevance of the surveillance system to the local community. Community members can clearly articulate their priority needs in a given context to ensure potential solutions align with those needs. The epidemiological context in Forest Guinea over the last 10 years makes this region an ideal laboratory for understanding how to tackle emerging infectious diseases in close cooperation with the people most affected