AC²TION project: Multicriteria analysis for decision support to evaluate the performance of new agroforestry systems in field crops[Projet AC²TION : Analyse multicritère pour l’aide à la décision afin d’évaluer les performances de nouveaux systèmes agroforestiers en grandes cultures]

The TETRAE project "Accelerating and Accompanying Transitions: Contributions and Impacts of Agroforestry in New Aquitaine" (AC²TION), aims to study the environmental and socio-economic performance of agroforestry systems (association of trees and crops on the same agricultural plot) in south-western France. As part of research component 3 of the TETRAE AC²TION project, we propose to present the methodological approach used to assess the environmental and socio-economic performance of field crop agroforestry systems at farm level in the Charentes region, using a multi-criteria decision-support method. By storing carbon, supporting a rich biological life in the soil and sheltering auxiliary insects in the canopy, trees play an active role in erosion control and soil conservation. Tree rows also play an important role as windbreaks and barriers to the atmospheric diffusion of pesticides. Trees create a habitat for crop pest beneficials, especially in areas where hedges and copses have long since disappeared. They can also act as a reservoir for fungal and bacterial pathogens. They also make the rural landscape a pleasant place to live. Agroforestry is therefore one of the levers that can support the agroecological transition to mitigate the effects of climate change, facilitate the implementation of other agroecological practices and provide ecological functionalities. The originality of our approach is twofold: 1) relatively few studies and applications have been carried out in New Aquitaine, in comparison with other regions such as Montpellier 2) at the heart of our questioning are the quantitative and qualitative decision levers and obstacles of agroforestry farmers in field crops. We propose to identify and classify their positive or deleterious effects, integrating them into an analysis of overall performance (environmental and socio-economic). Our methodological approach involves surveys and interviews with field crop agroforestry farmers, and analysis of the survey results, identifying the socio-economic and environmental decision factors involved in the transition. We will then use multi-criteria decision-support methods: Electre Tri-nC and Electre III to evaluate agroforestry performance. Qualitative and quantitative criteria will be used to understand the impact of such a system on microclimate and biodiversity. The same applies to soil enrichment for mineral plant nutrition, and positive externalities for humans. But agroforestry should also help reduce crop pathogens, with a view to reducing pesticide use. Anchored in the regional fabric of the Neo-Aquitaine region, the project is part of a strong partnership approach, with the French Agroforestry Association providing co-leadership. The Chambers of Agriculture of Charente Maritime and the Interdepartmental Chamber of Agriculture of Deux Sèvres and Charente-Maritime are also partners, as are several farmers. Our contribution to the project is also in collaboration with various arable and agroforestry farmers, based mainly in the Charentes region. Identification and classification of socio-economic and environmental decision criteria for the overall performance of field crop agroforestry farms.