Agroecology calls for a global approach, integrating scientific, practical, and advocacy dimensions, to redesign agricultural systems based on ecological and socio-cultural processes and emphasizing biodiversity. This review is grounded on the results of DIVERSIFOOD, a European H2020 multi-actor research project, and explores the concept of cultivated diversity using various dimensions relevant to foster sustainable organic food systems and agro-ecological transition. From the evaluation of underutilized genetic resources and forgotten crops, DIVERSIFOOD has proposed plant breeding strategies, on-farm experimentation, and statistical tools to create new populations, landraces, and organic cultivars with intra-varietal diversity. The added value of Community Seed Banks and forms of collective seed management in Europe have been described in terms of goals and activities, and their value for improving seed regulations, treaties, and genetic resources management is discussed. In the context of the current agro-food system characterized by standardization, DIVERSIFOOD raised awareness of qualities of ‘biodiverse food systems’ in which all actors have a role to play. It highlighted the critical capacity to preserve a diversity of cultural values embodied in ‘biodiverse products’, thereby involving consumers in collective strategies for reviving diversity, and empowering all actors of organic food systems to really and efficiently implement research within their farms and networks.

Modern agricultural systems rely on reduced crop genetic diversity, due in particular to the use of homogeneous elite varieties grown in large areas. However, genetic diversity within fields is a lever for a more sustainable production, allowing greater stability and resistance to biotic and abiotic stresses. In France, a Participatory Plant Breeding (PPB) project on bread wheat, involving farmers, facilitators and researchers, has led to the development of heterogeneous populations whose within-variety genetic diversity is expected to confer the ability to adapt to farmers’ practices and environments. We studied the stability and local adaptation of ten of these farmers’ populations as well as two commercial varieties in relation to their within-variety genetic diversity. Although no clear evidence of local adaptation was detected, we found that populations’ grain yield and protein content were more stable over space and time respectively than those of commercial varieties. Moreover, the varieties’ stability over time in terms of protein content was positively correlated with within-variety genetic diversity with no significant drawback on protein yield. These results demonstrate the wide adaptive potential of PPB populations, highlighting the importance of seed exchange networks for agrobiodiversity management and use. They emphasize the benefits of genetic diversity for stability over time, which is of great interest to farmers.

Participatory plant breeding (PPB) is based on the decentralization of selection in farmers’ fields and their involvement in decision-making at all steps of the breeding scheme. Despite the evidence of its benefits to develop population varieties adapted to diversified and local practices and conditions, such as organic farming, PPB is still not widely used. There is a need to share more broadly how the different programs have overcome scientific, practical, and organizational issues and produced a large number of positive outcomes. Here, we report on a PPB program that started on bread wheat in France in 2006 and has achieved a range of outcomes, from the emergence of new organization among actors, to specific experimental designs and statistical methods developed, and to populations varieties developed and cultivated by farmers. We present the results of a two-year agronomic evaluation of the first population varieties developed within this PPB program compared to two commercial varieties currently grown in organic agriculture. We found that several PPB varieties were of great agronomic interest, combining relatively good performance even under the most favorable conditions of organic agriculture and good robustness, i.e., the ability to maintain productivity under more constraining conditions. The PPB varieties also tended to show a good temporal dynamic stability and appeared promising for the farmers involved.

Dans les années 2000, des agriculteurs désireux de cultiver des blés correspondant à leurs besoins et soucieux d’affirmer leur autonomie vis-à-vis de l’industrie semencière, ont entrepris de relancer la sélection paysanne à la ferme. Des collaborations ont été tissées avec des généticiens de l’Inra, et se sont progressivement développées dans le cadre de projets financés. Or les financements de recherche impliquent une formalisation des partenariats, des engagements en termes de résultats académiques et une augmentation significative de la taille des projets. Dans ce nouveau contexte, comment préserver les valeurs d’émancipation paysanne et de justice cognitive sur lesquelles la collaboration paysans-chercheurs s’est originellement construite ? Cet article aborde la façon dont ce défi se pose concrètement aux acteurs de ces projets, et les précautions qu’ils mettent en œuvre pour y faire face. In the 2000s, a handful of farmers in France undertook to revive a practice fallen into disuse during agricultural modernization, i.e. on-farm plant breeding. Their motives were both to grow wheat varieties meeting their needs and to assert their independence towards the seed industry. Informal collaborations were woven with geneticists from the French institute for agronomic research (INRA), and developed further within the framework of funded projects. The foundations of a “decentralized participatory plant breeding” were then laid, both on a genetic rationale (breeding directly in the environments where the plants are to be grown) and on strong ethical principles (organizing non-hierarchical relations to let farmers question researchers’ assumptions). However, research funding involves a formalization of partnerships, commitments in terms of academic deliverables, and a significant increase in the size of projects. In this new context, how are the objectives of farmers’ empowerment and the values of cognitive justice on which the collaboration between farmers and researchers was originally built to be preserved? This article describes how this issue is actually tackled by the participants in these projects. We focus in particular on the debates raised by the creation of a database, and on the tensions it generates between centralization and decentralization. We also present the challenges raised by the dramatic increase in the number of participants, which risks to reproduce a division of tasks between researchers, farmers, and the people coordinating at a local level.

The industrialization of farming has significantly threatened cultivated biodiversity. Participatory breeding endeavours to overcome this issue by enabling farmers to select a wide range of crop varieties in different conditions, and to foster genetic mixing through seed exchanges, crosses or mixtures. This necessitates the design of new forms of coordination and organization for the farmers and partners involved. This article reports on an ongoing initiative, aiming to facilitate the participatory design of such forms of coordination and organization. It first outlines the method used (Knowledge–Concept–Proposals or KCP), and how it has been tailored to this highly decentralized context involving politically engaged actors on a quest for autonomy. It then presents the exploratory results of the first two workshops: these include group consolidation, the sharing of heterogeneous knowledge, the generation of innovative ideas, and the elaboration of preliminary projects. Finally, this empirical case is compared with other initiatives supporting the participatory design of natural resource management strategies and tools. Its key original dimensions and benefits are that the workshop protocol is replicable, the data produced can be easily exploited, and it allows for testing hypotheses in the field of design science.