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International audience; Assessing benefits and limits of agroecological transitions in different contexts is of foremost importance to steer and manage agroecological transitions and to feed evidence-based advocacy. However, assessing agroecological transitions remains a methodological challenge. The objective of this research was to investigate to what extent existing multiscale and multidimensional assessment methods were suitable to assess agroecological transitions. We used a literature review to identify and select 14 existing multiscale and multidimensional assessment methods related to sustainable or resilient agriculture. We then analyzed these 14 methods according to five evaluation criteria that reflected key requirements for assessing agroecological transitions: 1) be adaptable to local conditions, 2) consider social interactions among stakeholders involved in the transitions, 3) clarify the concept of agroecology, 4) consider the temporal dynamics of the transitions to better understand barriers and levers in their development and 5) use a participatory bottom-up approach. The methods adopted different approaches to consider each evaluation criterion, but none of them covered all five. The two evaluation criteria most often employed were the adaptability to local conditions (used by 13 of the methods) and the consideration of social interactions (used by all 14 of the analyzed methods). To be adaptable, methods mobilized generic guidelines with flexible content and/or included a contextualization phase. For social interactions, most methods mobilized social-related indicators, and two included stakeholder mapping. Two methods clarified the agroecological concept by mobilizing different sets of principles. Two other methods considered temporal dynamics of the transitions, mobilizing a trajectory of change to understand barriers and levers in their development. Finally, seven methods adopted a bottom-up participatory approach, involving stakeholders in both their development and use. To balance the existing trade-offs between the evaluation purpose, the time requirement and the level of participation in the different approaches adopted by the 14 methods studied, we suggest combining some of the approaches in a complementary mode to cover all 5 criteria and therefore improve the assessment of agroecological transitions.

In response to the sustainability issues that agriculture faces in advanced economies, agroecology has gained increasing relevance in scientific, political, and social debates. This has promoted discussion about transitions to agroecology, which represents a significant advancement. Accordingly, it has become a growing field of research. We reviewed the literature on and in support of farm transitions to agroecology in advanced economies in order to identify key research challenges and suggest innovative research paths. Our findings can be summarized as follows: (1) Research that supports exploration and definition of desired futures, whether based on future-oriented modeling or expert-based foresight approaches, should more explicitly include the farm level. It should stimulate the creativity and design ability of farmers and other stakeholders, and also address issues of representation and power among them. (2) Research that creates awareness and assesses farms before, during or after transition requires more holistic and dynamic assessment frameworks. These frameworks need to be more flexible to adapt to the diversity of global and local challenges. Their assessment should explicitly include uncertainty due to the feedback loops and emergent properties of transitions. (3) Research that analyzes and supports farms during transition should focus more on the dynamics of change processes by valuing what happens on the farms. Research should especially give more credence to on-farm experiments conducted by farmers and develop new tools and methods (e.g., for strategic monitoring) to support these transitions. This is the first review of scientific studies of farm transitions to agroecology. Overall, the review indicates that these transitions challenge the system boundaries, temporal horizons, and sustainability dimensions that agricultural researchers usually consider. In this context, farm transitions to agroecology require changes in the current organization and funding of research in order to encourage longer term and more adaptive configurations.

In the context of climate change and growing urbanization, farms are expected to face more frequent extreme events (e.g. heat peaks, droughts, frost, hail or floods). Floods being the natural hazard that generates the most damage in the world, we focus our research on the impact of floods on farms and their adaptation to climate change. Flood damage on farms is the result of complex phenomena involving biophysical processes on the one hand, and farmers' decisions on rehabilitation and adaptation on the other. Some impacts are directly visible; others may be delayed and persist over time (Bremond et al, 2013). When they persist over time, they may impact the development trajectory of farms. For the observation of impacts, there are in fact two challenges: to identify the diversity of impacts and their temporality of occurrence. Field surveys following flood events often focus on short-term damage and on impacts resulting from extreme events, leaving long-term damage and minor events aside. In this paper, we aim to propose a methodology that we are currently implementing to jointly and recursively improve the observation and modelling of flood impacts on agricultural systems. In particular, we wish to define more precisely the diversity of flood impacts and long-term damage on farms by taking into account the development trajectory of farms. To this end, we combine two complementary approaches: observation and modelling. Our work is implemented in the framework of the system of observations of the impacts of floods (so-ii, http://so-ii.org), in the Greater Montpellier area, coordinated by our team. Based on our experience, we have developed diverse methods for both short-term and long-term monitoring such as: surveys, participative workshops, drone pictures, predictive models. To cover on field-observations, quantitative and qualitative surveys have been carried out over the years on the so-ii territory. Interviews took place both after a flood, to gather quantitative data, and several years after a flood (Bremond et al, 2020), to collect quantitative and qualitative data. In parallel, we are exploring the use of drones to gather pictures of plots from post-flood to several years later in order to understand mechanisms behind the impacts of floods on soil, plant material and adaptations. To reinforce long-term monitoring, we have set up a network of impact observers, on the so-ii territory, with whom we agreed to work over the long-term (about fifteen years). On the other hand, we are working on the use of predictive models to estimate flood damage to farms. For now, 3 models have been developed: floodam.agri (Bremond et al, 2022), R-EVA (Bremond et al, 2012) and COOPER (Nortes Martinez et al, 2021). Each of these models have different application levels (respectively plot, farm and cooperative system) and time-scales which helps for the observation of farm trajectories as a whole. In conclusion, we will discuss the perspectives and limitations of this approach. We will open up on the perspectives to share our methodology so it can be adapted to other territories by stakeholders who are interested in setting up a similar system of observation.

International audience; In the global change context, an efficient management of the available resources has become one of the most important topics particularly for the sustainable crop development. Many questions concern the evolution of the rice farming systems in Camargue in Southeastern France, which play a crucial role in controlling the soil salinity. Their surface area significantly decreased from 20 000 ha in 2010 to 14 000 ha in 2014. The arrival of the new Sentinel satellites makes it possible to evaluate these crop evolutions. The objectives of this study were to propose operational methodologies to accurately assess the surface areas of the main crops, rice, wheat, and grassland, from classifications based on multispectral data; map agricultural practices (sowing and harvest residue burning); and elaborate a farm typology based on variables computed from remote sensing data to better understand the farming strategies. Dense time series of Sentinel images acquired at high spatial resolution (10 m) were analyzed for 2016 and 2017. A satisfactory accuracy was obtained for land use classification with 88% of correctly classified fields. The accuracy obtained for the estimation of the sowing date varied according to the studied year from 8 to 12 days, and burned areas were correctly identified (80%). The farm typology allowed to cluster farms at the territory level.

International audience; AbstractThe Companion Modeling approach aims to stimulate learning and sharing of perceptions among several actors through the co-construction and use of a model, while the Integrated Assessment of Agricultural Systems aims to assess a large set of performances of current and alternative systems. Our research question was: to what extent does the joint use of these two methods foster sustainability thinking? We show how the co-design of evolving agriculture scenarios and the use of Integrated Assessment of Agricultural Systems methods guided the implementation of a Companion Modeling process applied to the Valensole Plateau, southeastern France. An initial phase, based on a preliminary diagnosis, aimed to collectively formulate the issues to be addressed, and to engage the actors in a collective dynamic. The second phase consisted of leading actors in the co-construction of a simulation model to represent the agricultural system to be evaluated using economic, social, and environmental indicators at different scales. In the final phase, the current situation and the co-designed scenario were collectively analyzed. The scenario was conceived as a “worst case”, embedded with drivers such as input costs and climate change. Opposing adaptation strategies were envisioned by farmers and other actors. Results show how debates between participants adaptively shaped the model. Scenario simulations highlighted better environmental performance at the expense of economic performance. The differences between farms led to discussions on technical management. Overall, the process stimulated collective reflection among the actors and created a learning experience with the sharing of perceptions and knowledge about the agricultural system. The model was considered relevant by the participants, who expressed interest in continuing its exploration. Our approach, which used a unique combination of Integrated Assessment of Agricultural Systems and scenario development with Companion Modeling, could be adapted to other areas and issues, although tool transfer remains an open question.

International audience; Highlights:• We used a participatory approach to design adaptation strategies by spatially combining adaptation measures.• Adaptation strategies were evaluated by numerical modeling and stakeholder opinions such as feasibility and desirability.• A few adaptation strategies maintained vineyard production volume at mid-century, but with spatial heterogeneity.• Low yield production sectors, which were less impacted by climate change, showed higher adaptive capacity.• Researchers' and stakeholders' joint participation helped the design of locally pertinent adaptations to climate change.Abstract: Context: Climate change threatens wine growing systems in varying ways because of their high diversity, even at a local scale. This diversity needs to be considered when designing and assessing adaptation strategies to coordinate better with these diverse local conditions.Objective: We developed a participatory modeling approach to (1) design adaptation strategies in a viticultural watershed in southern France, (2) numerically and spatially evaluate their effects under future climatic conditions, and (3) discuss the results with stakeholders.Methods: We organized two sets of collective workshops, before and after a simulation phase. During the workshops, we designed four adaptation strategies that correspond to different ways to combine adaptation measures proposed by stakeholders. A spatially explicit model was used to evaluate the effects of six adaptation measures (late varieties, irrigation, reducing canopy size, adjusting cover cropping, reducing density, and shading) at field scale and combinations of them at watershed scale. Simulations were realized under a high-emissions climate change scenario RCP 8.5. Model-based evaluations were followed by discussions with stakeholders. The cost-effectiveness of adaptation strategies was estimated at farm scale using an indicator designed by the stakeholders.Results and conclusions: The spatial combination of adaptation measures in a viticultural watershed provided options for adapting wine growing systems to climate change. A delayed harvest strategy with currently available late varieties provided only minimal relief from high temperature during ripening. A water stress limitation strategy would compensate for production losses if disruptive adaptations (e.g., reduced density) were adopted and if more vineyards were irrigated. A relocation strategy would encourage premium wine production in the constrained mountainous areas, where grapevines systems are historically adapted to limited water conditions. A soil improvement strategy was mentioned but not evaluated in the model due to scarce data and literature on the possible improvement of soil water holding capacity.Significance: The sharing of knowledge between researchers, technical experts, and wine growers enabled the construction of a common understanding of the local impacts and adaptation potential to climate change in the watershed. In further research, this knowledge could help decision makers to define pathways for adaptive actions at farm scale.

International audience; The diversity of both pedoclimatic and socio-economic contexts in agricultural landscapes makes evaluating the impacts of climate change a challenge. Models are pertinent tools to quantitatively explore possible futures, and participatory approaches help account for local diversity. We developed a model through an approach that involves stakeholders in the model's construction and testing and in the discussion of results. We simulated spatially explicit impacts of climate change on water balance, grape phenology, and yield in a Mediterranean vineyard watershed for two climate scenarios. Results show a decrease in grape production of 7–14% by 2100. Yield decrease would be higher in irrigated high-yield areas despite a doubling of irrigation water supply. A forecasted 6 °C increase in temperature during berry ripening would threaten wine quality. The approach allows the communication of model results and limitations to stakeholders. It is a promising means of identifying potential local adaptations to climate change.

The frequent, widespread use of pesticides in agriculture adversely affects biodiversity, human health, and water quality. In 2008, the French government adopted an environmental policy plan, “Ecophyto 2018”, to halve pesticide use within 10 years. Trends in synthetic pesticide sales and use in France were described, through three different indicators: the number of unit doses (NUD), the quantity of active ingredient (QAI), and the treatment frequency index (TFI). Changes in pesticide use on seven of the principal arable crops in France since the implementation of this policy plan were analyzed, together with the impact of changes in pesticide use on water quality. No evidence was found for a decrease in pesticide sales at national level between 2008 and 2013. In terms of the TFI values for individual crops, the only decrease in pesticide use observed since 2001 was for soft wheat. This decrease was very slight, and pesticide use did not decline more rapidly after 2006 than before. Changes in pesticide use differed between French regions and crops. Water pollution did not decrease during the period studied. Possible explanations for the lack of effectiveness of the French environmental plan are considered in the context of European legislation.

Chapitre 10; National audience; Les mutations en cours au sein de l’agriculture interrogent les travaux et les méthodes relatifs à la conception de systèmes agricoles innovants. Ce chapitre analyse la spécificité de cinq démarches de co-conception de systèmes techniques testées en France et dans différents pays d’Afrique et d’Amérique latine. Elles se basent sur des interactions fortes entre les acteurs impliqués dans ces démarches, facilitées par une diversité d’objets intermédiaires tels que la modélisation ou l’expérimentation agronomique en milieu paysan. Elles ont permis de produire des connaissances opérationnelles et scientifiques sur des changements techniques et leurs conditions de mise en oeuvre à l’échelle de l’exploitation ainsi que sur les conditions institutionnelles favorables à l’émergence de nouveaux systèmes. Ces démarches mobilisent des compétences ne relevant pas seulement de l’agronomie. L’intégration de chercheurs relevant des sciences humaines s’avère centrale, en particulier pour analyser comment hybrider des connaissances multiples en vue d’accompagner l’innovation au sein des exploitations et des territoires.

[Departement_IRSTEA]Territoires [TR1_IRSTEA]SEDYVIN [ADD1_IRSTEA]Adaptation des territoires au changement globalCahier thématique; National audience; Ce deuxième cahier diffuse des connaissances scientifiques (non exhaustives) sur les effets du changement climatique sur l’agriculture et la forêt en Provence-Alpes-Côte d’Azur. Les cultures (vergers, céréales, riz, maraîchage…) et les forêts (feuillus, conifères) bénéficient des bienfaits du climat méditerranéen qui offre des conditions favorables au développement des plantes sous certaines conditions, mais souffrent aussi des événements extrêmes qui le ponctuent à intervalles irréguliers. Le climat méditerranéen qui sévit en région PACA pourrait se résumer par Toulourenc (« tout ou rien » en provençal), du nom du cours d’eau à caractère torrentiel qui coule dans la vallée étroite située au pied du versant nord du mont Ventoux. Avec le changement climatique actuel, les aspects négatifs de notre climat sont appelés à se renforcer et font déjà peser sur les terroirs agricoles et les forêts emblématiques de la région de nouvelles contraintes auxquelles il est nécessaire de faire face pour éviter des conséquences trop néfastes. Mais la pérennité et le développement des systèmes agricoles et forestiers ne dépendent pas seulement de l’évolution du climat. L’urbanisation, l’occupation des sols, les pollutions locales (sol, air, eau), les incendies, mais aussi les pratiques culturales et la gestion forestière, jouent un rôle fondamental. Il convient donc de privilégier une approche transversale. Cette publication souligne les conséquences du changement climatique sur l’agriculture et la forêt en prenant soin d’identifier les enjeux environnementaux, économiques et sociaux, les risques à l’échelle régionale et locale, mais aussi les solutions susceptibles de réduire les impacts (atténuation, adaptation) et les éventuelles opportunités à saisir. Comme dans le précédent cahier, la contribution des chercheurs et experts, exerçant leur métier en région PACA et dans les territoires limitrophes4, sous forme d’articles et de zooms, apporte des éléments de compréhension afin de mieux cerner les problématiques liées au changement climatique.