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International audience; Bioeconomy and circular economy have become key strategies in Europe since the 2000s, in order to shift away from fossil energy. Agriculture isat the heart of multiple issues: food, health, energy, biomaterials... While some agree that bioeconomy and circular economy have a significantpotential to contribute to the sustainable development goals and the Paris climate Agreement, there are many critics, especially because of the lackof questioning or evidence of the links between bioeconomy/circular economy and sustainability. Here, we start from the institutional definitionsof these two concepts to position the main criticisms that are made of them, but also the potentials. We will consider examples from the livestocksectors. We use criticism as a tool to unpack hidden assumptions and unanticipated consequences, and to re-evaluate what might otherwise betaken for granted, in order to discuss priorities so that bioeconomy and circular economy can be real means of achieving a sustainable society,and the place that livestock sectors can hold in; Bioéconomie et économie circulaire sont devenues des stratégies clés en Europe à partir des années 2000, visant à s'affranchir des énergies fossiles. L'agriculture se retrouve ainsi au cœur d'enjeux multiples : alimentation, santé, énergie, biomatériaux. Si certains s'accordent pour dire que bioéconomie et économie circulaire ont un important potentiel pour contribuer aux objectifs de développement durable et à l’Accord de Paris sur le climat, les critiques sont nombreuses, notamment du fait de l'absence de questionnements ou de preuves des liens entre bioéconomie/économie circulaire et soutenabilité. Dans cet article, nous prendrons comme point de départ les définitions institutionnelles de ces deux notions, pour mieux situer les principales critiques qui en sont faites, mais aussi les potentiels. Nous donnerons des illustrations dans le secteur de l'élevage. Ces critiques servent d'outil pour décortiquer les hypothèses cachées, les conséquences non envisagées, et réévaluer ce qui, autrement, pourrait être considéré comme acquis, pour discuter des priorités afin que bioéconomie et économie circulaire puissent être de réels moyens d'atteindre une société soutenable, et la place que peut y tenir l'élevage.

National audience; This document includes the scientific papers and their supports of the 1st GAMAE symposium which took place on 9 and 10 June 2022 in Clermont-Ferrand (France). The theme of the symposium was the assessment of serious games on agricultural, environmental and food issues.; Ce document regroupe les communications scientifiques et leurs supports du 1er colloque GAMAE qui s'est déroulé les 9 et 10 juin 2022 à Clermont-Ferrand (France). Le thème du colloque était l'évaluation des serious games sur les questions agricoles, environnementales et alimentaires.

In France, the intensification and specialisation of territories and farms have led to a dependence of livestock farms on the purchase of feed, particularly proteins, produced outside their territory, or even outside the country. This isparticularly the case for monogastric animals: pigs, chickens and ducks. The main protein food used for animal feed is oil cake, a co-product of the processing of soya, rape or sunflower seeds. In the hillsides of the Lauragais Tarnais,crop and livestock were formerly integrated. Now, as specialization towards cereal crop occurred, livestock farming is residual. Livestock are located on the rare grasslands (herbivores) or associated with field crop farms (monogastricanimals). However, despite a growing number of cereal-growing farms and strong crop diversification, crop and livestock are disconnected. Livestock farms and particularly those with monogastrics are strongly dependent fromimported proteins. Strengthening protein autonomy for monogastric farms at farm or region level is a strong regional issue. It is supported by the local agricultural actors, for economic and ecological reasons but also as a challenge forthe production of local quality products. It is an opportunity to initiate the agroecological transition of the region. Reconnecting crop and livestock productions implies changes for the livestock farms (e.g. rations), for crop farms (e.g.new crops, other rotations) and agri-chains (e.g. toasting soya). Identify the different levers and limits of a reconnection between crops and livestock as well as its local stakeholders could allow to strengthen protein autonomy. There is alsoa need to provide knowledge on the potentialities of the Lauragais territory in order to inform and inspire the different actors(/stakeholders ?). All that could be done through interviews with experts on livestock feeding, local expertson monogastric agri-chains and local farmers. The participatory approach will therefore be particularly important in this work to ensure the implementation of a dynamic that favours the territory’s protein autonomy. This presentationexplores how strengthening protein autonomy on mixed crop-livestock farms in the Lauragais Tarnais contributes to the agroecological transition.

International audience; Main resource for human and animal nutrition, agricultural biomass has also high potential uses as substitute for non-renewable resources in other sectors (construction, chemistry, energy, etc.).It plays an important role towards the energetic transition. In that regard, public institutions, particularly at local level, highly support new biomass uses for food and non-food uses, for products (e.g. grains,livestock) and co-products (e.g. straw, manure), leading to value chain reorganizations and/or creations. To prevent from de-structuring the other existing value chains, or from escaping local energetic,environmental or socio-economic issues, it seems important to understand the interactions between value chains in place. For that aim, the framework of metabolism seems particularly relevant. It allowsan analysis of the flows of materials and energy occurring between nature and society, between different societies, and within societies. Interactions between value chains can be characterized bymaterial flows and an analysis of actors which produce or use agricultural products and co-products. However, due to value chain specialties, the complexity of actor networks and highly diverse localities,these evaluations are difficult to undertake at local scales. Our goal here is to present and discuss an approach to account for interaction within and between agricultural value chains, based on a representation of material metabolism coupled with an analysis of actors’ networks. First, we build a theoretical metabolism, based on public databases to: i) inform on potential agricultural products and coproducts, ii) gather general information on local actors. Second, we lead a survey to consolidate this metabolism from the actual flows and develop a reading grid of actors’ networks based on the forms of: i) circulation of material flows between actors; ii) organization and coordination of this circulation of material flows between actors; iii) synergies, dependencies and competitions between actors around these material flows. The main challenge is to structure these interactions in a global representation of the local agricultural metabolism. We show an application of the method on two French localities that are contrasted in terms of agriculture in: i) the North of the Aube department, an area specialized in large field crops; ii) the Vallée de la Drôme, farm fields are four times smaller and the agriculture is more diversified with different types of crops and livestock systems. This method can be used with local partners as a reflexive tool on agriculture and value chains and as a starting point for foresight studies.

Integrating crop and livestock is broadly seen as an ideal option to maintain agricultural production levels while limiting environmental impacts on soil and biodiversity. Still, European crop-livestock farms keep declining due to globalized markets, agricultural policies and limited availability of workforce and skills. Reconnecting neighbouring specialized crop farms and livestock farms through grain, fodder, crop by-products and manure exchanges could be an alternative to overcome these limiting factors. Up to now, such collective organization is still rarely observed despite its potential advantages. In this study, we tried to understand farmers’ perceptions to highlight levers and barriers to crop-livestock integration beyond farm level. We analyzed interviews of 19 farmers interested in building such collaborations in Ariege, South- western France (8 crop farmers, 7 livestock farmers and 4 crop-livestock farmers). We observed different levels of involvement considered by the farmers ranging from wishing to buy local feed or establish new crops only if a local cooperative was creating contracts, to wishing to build a strong collaboration among local group over time. Different types of collective organization were mentioned, ranging from polycentric organization involving only farmers up to a governance through a local cooperative. The main barriers were related to logistics and storage, timemanagement, low costs of inputs as regards to the time needed to implement such local cooperation, and establishment of trust. The main levers were the existence of local cooperatives or machinery groups that could drive the project and establish contracts, new policies oriented toward collective actions and a niche-market that recognized the interest of local feed for livestock. We highlighted a strong implicit divergence between the mindsets of crop farmers relative to livestock farmers that could hinder this type of local cooperation as they have few relationships and low trust. We suggest that farmers that already have both crops and livestock may be an ideal-type to improve ties between specialized farmers. In-depth analysis of farmer motivations and long-term efforts to build strong local networks and new policies would thus be key to favour the development of crop-livestock integration beyond farm level.

Document de synthèse dont l'objectif est de proposer des éléments pour renforcer l’autonomie protéique des élevages de monogastriques du Lauragais afin d’engager la transition agroécologique à l’échelle de l’exploitation et/ou du territoire.

International audience; configured with available data on savannah agroecosystems in West Africa. It focuses on processes related to nitrogen (N), a key limiting resource for both plant and animal production. It was implemented with Gama (v1.8). Model evaluation was based on field-data from two villages of the Groundnut Basin in Senegal, where agropastoralists have contrasted farming practices. It showed that the model reproduces the differences between an “extensive” and an “intensive” system. In a context where historical quantitative data on nutrient flows are lacking, the model was used to explore past agroecosystems functioning and performances regarding N flows. Simulations highlighted bottlenecks along the N cycle like accumulation of N in manure heaps and housing areas, reducing N recycling efficiency, especially in “intensive” systems. Two major properties appeared to be outlasting the transition: i) independence towards external inputs, based on croplivestock integration; ii) spatial heterogeneity due to nutrient transfers from peripheral land units to core land units, mainly through livestock. This model can be further used to explore improved agro-sylvo-pastoral landscapes. Processes related to carbon sequestration can also be implemented.

International audience; The bioeconomy has become politically unavoidable for the transition to a carbon-free economy. It promotes the development of non-food uses of agricultural biomass. However, few methods and tools allow us—without prior fieldwork—to outline hypotheses on the bioeconomic functioning of a territory, from the stages of agricultural biomass production to its valorization. Thus, this article proposes an operational metabolic approach, based on open data, and a framework for analysis that deals with dimensions of embeddedness, autonomy, and energetic, environmental, and socioeconomic footprints. This proposal is put to the test within two territories, enabling a preliminary assessment to be made before any field application.; La bioéconomie est devenue incontournable pour la transition vers une économie décarbonée. Elle favorise le développement des usages non alimentaires des biomasses d’origine agricole (BOA). Or peu de méthodes et outils permettent – sans travail de terrain préalable – d’esquisser des hypothèses sur le fonctionnement bioéconomique d’un territoire, des étapes de production des BOA jusqu’à leur valorisation. Ainsi, cet article propose une approche métabolique opérationnelle, à partir de données en libre accès, et une grille d’analyse traitant des dimensions d’ancrage, d’autonomie et d’empreintes énergétique, environnementale et socio-économique. Cette proposition est mise à l’épreuve de deux territoires, permettant un diagnostic préliminaire à une application sur le terrain.

This CORE Organic Practice Abstract gives practical recommendations for multi-species livestock farming, which has the potential to improve the three dimensions of sustainability – economic viability for farmers, environmental soundness, and social acceptability – by being respectful of animals and humans, as long as locally relevant farming practices are implemented, especially an appropriate stocking rate during grazing.

Keeping two or more livestock species or categories on the same farm simultaneously is a diversification option that has received little attention to date. We surveyed 95 organic multi-species livestock farms across six European countries to build a farm typology and characterise their diversity in structure, management, and performances. Farms combined cattle (meat, milk), small ruminants (meat, milk) and/or monogastrics. Survey data on the structure, management, and performances allowed for the creation of indicators (including farmer’s satisfaction) used to run a principal component analysis and an agglomerative hierarchical clustering to build the farm typology. The following variables structured the first four factors of the PCA: F1: Farm size and crop-pasture balance; F2: Intensification - Feed self-sufficiency; F3: Work productivity - Diversification activities and marketing; F4: Dairy cattle and permanent pasture. Four groups of farms emerged from the clustering: G1: Large area with a high share of crops, low feed autonomy, dairy cattle with beef cattle or pigs, on-farm processing, short sale channels and agritourism; G2: Prevalence of poultry with beef cattle, leading to high labour productivity and low feed autonomy, although ruminant diets highly rely (90%) on fodder; G3: Beef cattle associated with meat sheep, high feed autonomy, frequent short sale channels; G4: Italian farms with predominantly dairy ewes and dairy or meat cattle, rangelands, on-farm processing and short sale channels. Our next objective is to study the relationships between agricultural practices, work organisation, sales management and farm performances.

The strong development of non-food uses of biomass of agricultural origin (BAO) questions the competition of use of these biomasses and re-structuring of value chains at a local scale. To develop a territorial bioeconomy, one issue is to characterize the BAO, its ways of valorization and associated actors. This communication describes a metabolic approach of the functioning of the value chains using the BAO at local scale. This approach can be used to build a tool used to exchange with local stakeholders to i) integrate their knowledge with data from databases; ii) encourage their reflexivity and, even, implement territorial prospectives., Le fort développement des usages non alimentaires des biomasses d'origine agricole (BOA) questionne les concurrences d'usage de ces biomasses et la re-structuration des filières à l'échelle des territoires. Pour développer une bioéconomie territoriale, un des enjeux est de caractériser la BOA, ses modes de valorisation et les acteurs associés. Cette communication présente une approche métabolique du fonctionnement des filières utilisant la BOA d'un territoire. Cette approche permet de construire un outil d'échange avec les acteurs des territoires pour i) intégrer leurs connaissances à des données issues de bases de données ; ii) susciter leur réflexivité voire, de mettre en œuvre des prospectives territoriales.

National audience; The strong development of non-food uses of biomass of agricultural origin (BAO) questions the competition of use of these biomasses and re-structuring of value chains at a local scale. To develop a territorial bioeconomy, one issue is to characterize the BAO, its ways of valorization and associated actors. This communication describes a metabolic approach of the functioning of the value chains using the BAO at local scale. This approach can be used to build a tool used to exchange with local stakeholders to i) integrate their knowledge with data from databases; ii) encourage their reflexivity and, even, implement territorial prospectives.; Le fort développement des usages non alimentaires des biomasses d'origine agricole (BOA) questionne les concurrences d'usage de ces biomasses et la re-structuration des filières à l'échelle des territoires. Pour développer une bioéconomie territoriale, un des enjeux est de caractériser la BOA, ses modes de valorisation et les acteurs associés. Cette communication présente une approche métabolique du fonctionnement des filières utilisant la BOA d'un territoire. Cette approche permet de construire un outil d'échange avec les acteurs des territoires pour i) intégrer leurs connaissances à des données issues de bases de données ; ii) susciter leur réflexivité voire, de mettre en œuvre des prospectives territoriales.

Agro-sylvo-pastoral systems (systèmes agro-sylvo-pastoraux - SASP) of West Africa are agroecosystems limited in biomass and nutrients. Nutrient recycling and fertility transfer are traditionally driven by the mobility of ruminant herds led in extensive practices. Agro-pastoralists practice night corralling of their herds to concentrate the organic matter in the fields near the houses, in order to secure a sufficient food production for their needs.In a context of demographic growth and the reduction of natural rangelands in favor of cultivated areas, the "traditional" mobile livestock system, based on high mobility within the village is being called into question. The strategies adopted by the agro-pastoralists are: (i) keeping the herds away from the village for periods of varying lengths, by seasonal transhumance in less populated regions where forage resources are more important, or (ii) more recently, intensified practices with animals kept in the barn within the village and fed with concentrate feeds, bought on the local markets. These changes in livestock systems may have important consequences for biomass flows and nutrient cycling at the household and village landscape level. There was a need to assess their impact on the functioning and sustainability of SASP.To this end, the TERROIR multi-agent model has been developed and implemented on the GAMA modeling platform. It simulates the effect of changes in the organization of the landscape and livestock systems on biomass and nitrogen flows at different levels of organization in the village: plot, herd, household, village landscape. The model simulates the exchanges of biomasses between dozens of households with different strategies and practices. It includes the spatial transfers of biomasses between several hundred plots orchestrated by dozens of herds moving independently. The model synthesizes these flows with a set of indicators from two methods of analysis (Ecological Network Analysis and System Gate Balance) to describe the structure, functioning and sustainability of the agroecosystem, in terms of productivity, efficiency, autonomy, recycling, spatial transfers and nutrient balance. The model was designed and configured with available data on savannah agroecosystems in West Africa. It was evaluated from data observed in two villages of the Groundnut Basin in Senegal where the practices of agro-pastoralists are particularly contrasted.The TERROIR model was developed and implemented to explore the impacts of the village dynamics observed over the period 1920-2015 in the Groundnut Basin in Senegal, an agricultural zone in fast and advanced agrarian transition. The results highlight a reorganization of the nitrogen cycle and a general trend towards increased flows and increased dependence of agroecosystems on external sources of nutrients. However, the recycling and spatial transfers of nutrients internal to agroecosystems remain at high levels. The soil-plant-animal-human integration and the spatial heterogeneity of the distribution of fertilizing resources appear as two persistent properties of the studied agro-ecosystems. Consolidating this integration and spatial organization could guarantee for the sustainability of future farming systems that will emerge in a context of continued high-population growth and climate change.; Les systèmes agro-sylvo-pastoraux (SASP) d’Afrique de l’Ouest sont des agro-écosystèmes limités en biomasses et en nutriments. Le recyclage des nutriments et les transferts de fertilité sont traditionnellement rythmés par la mobilité des troupeaux de ruminants conduits en extensif. Les agro-éleveurs pratiquent le parcage nocturne de leurs troupeaux pour concentrer la matière organique, dans les champs à proximité des habitations afin de sécuriser une production vivrière suffisante à leurs besoins. Dans un contexte de croissance démographique et de réduction des parcours naturels au profit des zones cultivées, le système d’élevage « traditionnel », basé sur une forte mobilité intra-terroir villageois, est remis en cause. Les stratégies adoptées par les agro-éleveurs sont, soit (i) l’éloignement des troupeaux du terroir villageois pendant des périodes plus ou moins longues par des pratiques de transhumance saisonnière vers des régions moins peuplées et disposant de davantage de ressources fourragères ; soit (ii) plus récemment, des pratiques d’intensification avec des animaux gardés à l’étable au sein du terroir villageois et nourris avec des aliments concentrés, achetés sur le marché local. Ces changements de systèmes d’élevage ont possiblement des conséquences importantes sur les flux de biomasses et les cycles des nutriments au niveau du ménage et du territoire. Il convenait de les évaluer en termes d’impacts sur le fonctionnement et la durabilité des SASP.A cet effet, le modèle multi-agents TERROIR a été développé et implémenté sur la plateforme de modélisation GAMA. Il simule l’effet de changements dans l’organisation du paysage et des systèmes d’élevage sur les flux de biomasse et d’azote aux différents niveaux d’organisation du territoire : la parcelle, le troupeau, le ménage et le terroir villageois. Le modèle simule les échanges de biomasses entre une centaine de ménages comportant des stratégies et des pratiques différentes. Cela inclut les transferts spatiaux de biomasses orchestrés par plusieurs centaines de troupeaux se déplaçant de façon indépendante sur un millier de parcelles. Le modèle synthétise ces flux par un ensemble d’indicateurs issus de deux méthodes d’analyse (« Ecological Network Analysis » et « System Gate Balance ») pour décrire la structure, le fonctionnement et la durabilité de l’agroécosystème, en termes de productivité, d’efficience, d’autonomie, de recyclage, de transferts spatiaux et de bilan de nutriments. Le modèle a été conçu et paramétré à partir des données disponibles sur les agroécosystèmes de savane en Afrique de l’Ouest et il a été évalué à partir des données observées dans deux terroirs villageois du bassin Arachidier au Sénégal où les pratiques des agro-éleveurs sont particulièrement contrastées.Le modèle TERROIR a été utilisé pour explorer les impacts des dynamiques territoriales observées sur la période 1920-2015 dans le bassin Arachidier au Sénégal, une zone agricole à transition agraire rapide et avancée. Les résultats soulignent une réorganisation du cycle de l’azote et une tendance générale à l’intensification des flux et à l’augmentation de la dépendance des agroécosystèmes vis-à-vis de sources extérieures de nutriments. Cependant, le recyclage et les transferts spatiaux de nutriments internes aux agrosystèmes restent à des niveaux élevés. L’intégration sol-plantes-animaux-hommes et l’hétérogénéité spatiale de la répartition des ressources fertilisantes apparaissent comme deux propriétés persistantes des agro-écosystèmes étudiés. Consolider cette intégration et cette organisation spatiale seraient ainsi un gage pour la durabilité des futurs systèmes agricoles qui émergeront dans un contexte de poursuite de la forte croissance démographique et de changement climatique.

National audience; Biomass recycling plays a key role in the functioning of agro-silvopastoral systems. InWest Africa, the variability of rainfall impacts the management of this biomass to feed men, livestock, soil and plants. This study describes a conceptual model of action, based on “if-then-else” rules, which represent the management decisions of the biomass by the farm households. The study underlines the cascading consequences of rainfall hazard on the farming activity schedule, the quantities and the nature of the mobilized biomasses. The most directly impacted activities are planting and harvesting of crops, animal feeding and, indirectly, soil fertilization and the management of food stocks. The action model encompasses the management rules and conditions constituting the practices of the farm households. It is defined for four types of mixed crop-livestock households defined according to their dominant activities: crop versus livestock, and food versus income. Food and livestock households are more sensitive to rainfall variations. They present a type of management that is more adaptive because they are more dependent on their own produced biomasses. This action model was designed for its integration into an agent-based model to simulate the consequences of climatic hazards on biomass flows resulting from interactions between diverse households in a typical West African village.; Le recyclage de la biomasse végétale et animale joue un rôle central dans le fonctionnement des systèmes agro-sylvopastoraux. En Afrique de l’Ouest, la variabilité des précipitations impacte les pratiques de gestion de cette biomasse pour nourrir les hommes, le bétail, le sol et les plantes. Cette étude décrit un modèle d’action conceptuel basé sur des règles « si-alors-sinon » qui représentent les décisions de gestion de la biomasse des ménages agricoles. L’étude souligne les conséquences en cascade d’un aléa pluviométrique sur le calendrier des activités agricoles, les quantités et la nature des biomasses mobilisées. Les activités les plus directement impactées sont le semis et la récolte des cultures, l’alimentation animale et, indirectement, la fertilisation des sols et la gestion des stocks alimentaires. Le modèle d’action regroupe les principales règles et modalités de gestion constituant les pratiques des ménages agricoles. Il est défini pour quatre types de ménages agriculture-élevage selon leurs activités dominantes : agriculture versus élevage et vivrier versus vente. Les ménages vivriers et élevage sont plus sensibles aux variations pluviométriques. Ils présentent une gestion plus adaptative car ils sont davantage dépendants de leur propre production. Ce modèle d’action a été conçu en vue de son intégration dans un modèle à base d’agents pour simuler les conséquences de l’aléa pluviométrique sur les flux de biomasses résultant des interactions entre les ménages agricoles d’une communauté villageoise en Afrique de l’Ouest.

This papers appears in Volume 5; National audience; Biomass recycling plays a major role in the functioning and sustainability of agro-silvo-pastoral ecosystems in West Africa. However, farming systems must adjust rapidly to changing landscapes. This abstract describes an Agent-Based Model (ABM) that analyzes nutrient (N) cycles within the village “terroir” agro-ecosystem to assess how changes in land use and farming practices affect croplivestock integration and spatial heterogeneity. The ABM is implemented on the GAMA platform (Generic Agent-based Modelling Architecture). Each simulated household is classified according to a farm type with a pre-defined biomass management strategy (use of crop products, manure, etc.). The model is spatially explicit, with biomass being moved across landscape units and through different ecosystem components: soil, plants, animals, humans, etc. Biomass flows are converted into N flows which are then used to calculate indicators such as N balance, N use efficiency, and the diversity and recycling indexes that characterize N cycles. The model was parameterized through on-farm measurements of crop and livestock productions (for the biophysical sub-system) and participatory workshops with farmers (for the decision sub-system). The model was validated on the basis of biomass flows observed in two villages in the Senegalese groundnut basin. The model is original in its multi-scale analysis of N cycles occurring at different organizational levels: plot, herd, household and landscape. For instance this highlights the consequences of households' choices at the plot scale for spatial heterogeneity at the landscape scale. This ABM is potentially generalizable for designing ecological intensification pathways in West African village “terroirs”.

Free-range and common-grazing ruminants play a major role in the functioning and the provision of ecosystem services by agro- and silvo-pastoral ecosystems in sub-Saharan Africa. To assess how landscape structure affects the nature of environment-herd-services interactions, this paper describes a Multi-Agent System (MAS) that simulates daily herd movements in a dynamic environment. The model is used to study how the overall productivity of an agricultural territory is affected by the spatial organization of its different landscape units. The originality of this model lies in fine representation, in hourly time steps, of a herd's movements and activities over the seasons depending on changes in its environment. The herd is likened to a reactive agent with a global representation of its environment. It moves, grazes, drinks, rests and defecates. The model represents the spatio-temporal takeoff of biomass and animal faeces deposits. Grazing occurs between the moving, watering and resting phases, while defecation is continual. Biomass ingestion depends on its relative abundance in the explored plots, while the amount of faeces excreted depends on the amounts of biomass ingested the previous day. This paper describes the first use of the model on a choreme type environment representing a theoretical village territory typical of those found in West Africa. It comprises 5 landscape units: dwellings, compound fields, bush fields, fallows and rangelands. Two scenarios corresponding to 2 different landscape structures were simulated: alley fallows (Sc1), scattered fallows (Sc2). Most faeces deposits were in the fallows (sc1) or rangelands (sc2) in the wet season (4 out of 12 months) and in compound fields in the dry seasons (8 out of 12 months). Alley fallows (sc1) helped to intensify fertility transfers from rangelands to cultivated zones, thereby increasing productivity in cultivated zones (+26%) to the detriment of rangelands (-68%). The presence of ruminants in the territory therefore helped to i) enhance the positive effect of fallows and rangelands in renewing the fertility of cultivated soils and ii) maintain a system of concentric fertility rings with a decreasing fertility gradient from the core (=dwellings) to the periphery of the village (= rangelands). This modelling work thus helps to explain how landscape heterogeneity seen in African village territories is constructed.

International audience