Agroecology and public policy instruments for sustainable multifunctional agricultural landscapes

Project leaders: Vincent MARTINET (Économie Publique) & Muriel Tichit (SADAPT: sciences action development - activities products territories).           Project type and date: flagship project 2016-2020          Project acronym: API-SMAL 

Partners

• in BASC: Agronomie, BIOGER (Biology and risk management in agriculture), ESE (Ecology, systematics and evolution)
• academic outside BASC: BioSP, MaIAGE
• non academic : CDC-Biodiversité, FNCIVAM

The agro-ecological transition relies on the mobilization of ecological dynamics and the provision of ecosystem services to both improve the performance of agriculture and reduce its environmental impacts. The associated changes in practices are presented as benefits for farmers, as they aim to improve pollination, soil fertility and biological control of pests, for example, but also as means to contribute to major global challenges, such as climate change mitigation or biodiversity preservation. Promoting certain ecological functions requires modifying the ecosystem in a particular way at scales ranging from the plot to the landscape. As such modifications can affect several ecosystem services simultaneously, the levers considered for a sustainability issue can be antagonistic to other issues. It is therefore necessary to study the synergies and antagonisms between agroecological practices in order to clarify the trade-offs between different sustainability issues in agricultural systems.

The literature generally studies the effect of an agroecological lever on a few issues, but there are few analyses of the effects of combinations of agroecological practices on service packages. The compatibility of different agroecological solutions is rarely studied. The API-SMAL project aimed to provide a more global view by examining the feasibility and consequences of combining different agroecological solutions in time and space to define truly multifunctional and therefore more sustainable agricultural landscapes. To do this, we considered many sustainability issues together and examined how different practices described in the agroecology literature affect them. We then examined the compatibility between these practices at different scales and how they can be combined over time and space to achieve given sustainability goals. We then sought to assess, via modeling, how different land use scenarios influence the multi-performance of agricultural landscapes.

The API-SMAL project involved researchers from seven laboratories in an interdisciplinary work (economics, agronomy, ecology, agroecology, epidemiology and modeling). The consortium also involved two non-academic partners who brought us their field experience on the implementation of agroecology by farmers (Réseau CIVAM) and on the economic instruments that can accompany the agroecological transition (CDC-Biodiversity).

The work carried out in the project has made it possible to examine the synergies and antagonisms between agricultural sustainability issues in a context of agroecological transition. These results benefit both the agricultural world, through the multi-issue analysis we have produced, and public decision-makers who wish to support the agro-ecological transition through incentive policy tools. Here are three examples.

A literature review analyzing the effect of agroecological practices on different sustainability issues allowed us to establish a network linking all the practices identified as promising to all the issues studied. We have identified "win-win" practices that have a beneficial effect on all the issues (e.g. crop diversification), and practices that should be deployed with caution because they can have negative effects on certain issues in certain circumstances (e.g., the impact of the presence of wood on crop health), and potentially controversial practices in the sense that they have negative effects on non-targeted issues (e.g., the reduction of tillage, which can increase the sources of inoculum for certain diseases, or be accompanied by an increased use of herbicides, leading to an increase in pollution) The innovative aspect of this work is that it brings together studies focused on various practices and different issues. The network can be enriched by new knowledge and serve as a dialogue tool for stakeholders.

We then analyzed the effect of the increase of semi-natural habitats on different issues (production, crop protection, carbon sequestration). To do so, we coupled three models considering different scales, local (agricultural landscape), regional (departmental mesh) and national (regional mesh). This allowed us to study the trade-offs between ecosystem services at different scales. The methodological challenge was to couple models designed to study different ecosystem services at different scales, with the main common element being the consideration of semi-natural habitats. Our work is an innovative attempt at multi-scale coupling to study the provision of ecosystem services. It is based on the original idea of creating a common formalism between the models that allows their coupled use.

We also studied the extent to which the various incentive instruments available to regulators can be mobilized and adapted to meet the challenges of the agro-ecological transition. As ecosystem services are based on complex temporal and spatial dynamics, it is necessary to involve the right actors in the long term and to coordinate their actions in space, which is a major challenge for the design of public policies.

The research theme of the API-SMAL project continues to offer opportunities for interdisciplinary collaboration on the links between agroecology and economics, particularly in designing multifunctional agricultural landscapes and the public policy instruments to implement them.

Publications 

International journals:

> Delaune T, Ouattara M S, Ballot R, Sausse C, Felix I, Maupas F, Chen M, Morison M, Makowski D, Barbu C. 2021. Landscape drivers of pests and pathogens abundance in arable crops. Ecography. https://doi.org/10.1111/ecog.05433. Short abstract: "We sought to identify general rules characterizing the impact of the landscape on the prevalence of pests and pathogens of arable crops. We showed that the host crop area is consistently correlated with increased pressure of the pests and pathogens the following growing season. Correlations of pests and pathogens with host crop areas in the same year or with semi-natural components of the landscape (grasslands, hedgerows and forests) are less consistent and depend on the functional traits of the organisms involved."

> Legal, A., Robert, C., Accatino, F., Claessen, D. & J. Lecomte. 2020. Modelling the interactions between landscape structure and spatio-temporal dynamics of pest natural enemies: Implications for conservation biological control. Ecological Modelling. 420, 108912

> P.Y. Hardy, A. Dray, T. Cornioley, M. David, R. Sabatier, E. Kernes, V. Souchère, 2020.  Public policy design: Assessing the potential of new collective Agri-Environmental Schemes in the Marais Poitevin wetland region using a participatory approach, Land Use Policy, 97, 104724

> Accatino et al., 2019 - Accatino, F., Tonda, A., Dross, C., Léger, F., Tichit, M., 2019. Trade-offs and synergies between livestock production and other ecosystem services. Agricultural Systems, 168, 58-72

> Courtois, P., Gueye, M., Martinet, V., Préget, R., Salles, J.-M., SAUQUET, A., Soubeyran, R., Subervie, J., 2019. Quelles politiques publiques pour favoriser des paysages agricoles multifonctionnels? In: Sandrine Petit, Claire Lavigne, dir., Paysage, biodiversité fonctionnelle et santé des cultures. Sciences en Partage (Quae). Versailles, FRA : Editions Quae.** 

> Hannachi, M., Martinet V., 2019. Vers une co-conception de paysages pour la santé des plantes et avec des acteurs du territoire. In Sandrine Petit, Claire Lavigne, dir., Paysage, biodiversité fonctionnelle et santé des cultures. Sciences en Partage (Quae). Versailles, FRA : Editions Quae** 

> Kerdraon L, Laval V, Suffert F, 2019. Microbiomes and pathogen survival in crop residues, an ecotone between plant and soil. Phytobiomes Journal 3: 246-255. https://doi.org/10.1094/PBIOMES-02-19-0010-RVW 

Oral communications:

The project leader explains the projects and its RESULTS in VIDEO (2020 scientific days of LabEx BASC, November 27, 2020) 

> Accatino, F., Tonda, A., Tichit, M. -  Exploring tradeoffs and synergies between food production and carbon sequestration in a grassland-dominated landscape based on extensive cattle systems, Presentation IALE 2019 (Milan)

> Colas, F., Norville, J., Labarthe, S., Martinet, V., Accatino, F., 2019. Interaction entre différents modèles d’agroécologie pour étudier des compromis entre services écosystémiques à différentes échelles du paysage. Presenté aux Rencontres d’Ecologie des Paysages 2019, Bordeaux, France, 5-7 novembre 2019, pp. 40-41.

> Colas, F., Norville, J., Labarthe, S., Martinet, V., Accatino, F., 2019. Interplay of agroecology models in the study of landscape ecosystem services trade-offs. Presented at the 10th IALE World Congress, Milan, Italy, p. 337.

> Devaud, N and Barbu, CM. Quantification de l'efficacité des pratiques de contrôle des maladies en grandes cultures en France. Végéphyl – 12e Conférence internationale sur les maladies des plantes. Tours – 11 ET 12 décembre 2018, Tours.

> Barbu, C. M.; Chen, M.; Guérin, N.; Simmoneau, D.; Valentin-Morison, M.; Sausse, C. & Félix, I. (2017), 'Regards croisés sur l'effet des espaces semi-naturels et de l'assolement sur les bio-agresseurs de grandes cultures'', AFPP – 6e conférence sur les moyens alternatifs de protection pour une production intégrée

Book chapters:

> Sandrine Petit, Stéphanie Aviron, Thierry Caquet, Marc Deconchat, Sabrina Gaba, Chantal Gascuel, Herve Jactel, Mourad Hannachi, Claire Lavigne, Vincent Martinet, Julien Papaix, Olivier Plantard, Lionel Ranjard, Marc Voltz  (2020). Valoriser les processus écologiques, hydrobiogéochimiques dans des paysages multifonctionnels. In Dedieu B., Detang-Dessandre C., Dupraz P., Hinsinger P., Médale F., Reboud X., Soussana J-F., and Thomas A. L’agroécologie : des recherches pour la transition des filières et des territoires. Collection Matière à débattre et décider, Éditions Quæ, pp.47-58, 2020, 978-2-7592-3129-4

> Courtois P., M. Gueye, V. Martinet, R. Préget, J.-M. Salles, A. Sauquet, R. Soubeyran, J. Subervie (2019) `Quelles politiques publiques pour favoriser des paysages agricoles multifonctionnels ?' in Paysage, biodiversit e fonctionnelle et sant e des cultures, Sandrine Petit, Claire Lavigne (dir.), Sciences en Partage (Quae). Versailles, FRA : Editions Quae.

> Martinet V., David M. and Langlois B. (2019) `Evaluation économique du service de régulation de la santé des cultures', in Paysage, biodiversité fonctionnelle et santé des cultures, Sandrine Petit, Claire Lavigne (dir.), Sciences en Partage (Quae). Versailles, FRA : Editions Quae.

> Martinet V. and Hannachi M. (2019) `Vers une co-conception de paysages pour la santé des plantes et avec des acteurs du territoire', in Paysage, biodiversité fonctionnelle et santé des cultures, Sandrine Petit, Claire Lavigne (dir.), Sciences en Partage (Quae). Versailles, France