1In this issue, we present a wide range of texts about the diversity of maize in Mexico in relation to peasant agricultural practices. The scientific debates on this theme form part of a line of reflection about the conservation of biodiversity that the Revue d’ethnoécologie has been featuring and fostering for some time. The authors of the present issue share the same research object, maize, which they examine on various scales and from a wide variety of observation points (direct experiences, national analyses, local studies): why and for whom should we conserve agricultural biodiversity (Bahuchet et al. 2000, Rodríguez 2011, Swart et al. 2018)? How can an object such as this one, which is in constant evolution, be studied and measured? (Aguirre Salcedo & Ceccon 2020, Nicholls et al. 2020, Iermanó et al. 2020) How can practices and phenomena that conserve this diversity, but at the same time transform it, be analyzed (Dumez 2010, Cunha Ávila et al. 2017)? The importance relevance of certain analytical categories, and the connections between biodiversity and cultural diversity (Virtanen 2019, Roué 2006), are also at the heart of these texts. In Mexico, these questions have aroused interest in the fields of anthropology and ecology. But they have also been studied by agronomists involved in research programs in support of peasant agriculture.

3Reflection around geographical distribution, conservation and on-farm management of the diversity of Mexican maize constitute a thread running through all of the articles in this special issue. The body of research conducted on this species in its center of origin, Mexico, is quite extensive. Over the past twenty years it has given rise to many questions and controversies around issues such as the genetic erosion of maize (Dyer et al. 2014, Perales & Golicher 2014, Brush et al. 2015). Far from wanting to draw unequivocal conclusions about these issues, here we look back at these debates through the prism of the place of peasant agriculture and local varieties in Mexican agriculture. Through the broad array of ideas and approaches represented in this issue, and through local experiences and analyses based on national-level studies, we hope to have contributed to the development of new avenues for the study of maize conservation in Mexico. The Mexican case is particularly well suited to exploring the various issues that surround and depend on the legitimacy and specificities of crop diversity conservation, as opposed to so-called “wild” biodiversity, especially in institutional arenas.

7What, then, is keeping not biodiversity itself, but the conditions that enable it to persist – agricultural practices, the biological and cultural dynamics that underlie it—from being valued and supported?

8The texts collected here identify certain trends and transformations, without limiting themselves to calculating the diversity of maize varieties and analyzing their distribution. They give a central place to farmers’ practices, and enable us to understand crop diversity as the result of farmers’ efforts to adapt simultaneously. The multiplicity and transformations of traditional agricultural systems are illustrated in these texts with the example of the “milpa”, an area of maize cultivation that is typical of the Mexican slash-and-burn agricultural system. In both scientific and popular literature, this system is described as characterized by the combination of maize, beans and squash. The reality, however, features a range of practices which are often not included in this pattern. In milpas, we can find commercial cultivations meant for sale. Often, milpas also appear in the form of a maize monoculture dedicated to self-consumption, which peasants who are busy with other activities, including non-agricultural ones, perceive as a means of profiting from the resources available to them. But attention to cultural practices must not be limited to the observation of work in the fields. Taking an interest in the diversity of maize will lead us to discover that the borders between criollo, native, modern and hybrid varieties of maize are made permeable by farmers’ practices and the constant circulation of seeds. These borders thus tend to fade or be erased by the inventive activity of farmers themselves, who often do not see their maize in terms of these categories, and who continuously create populations that are increasingly adapted to their needs. There thus tend to be significant discrepancies between widespread ideas about traditional peasant agriculture and the multitude of agro-ecologies in action in Mexico. In approaching questions of conservation, then, we must take into account a more complex and problematic socio-economic and ecological reality.

9This collection aims to bring together highly varied experiences and analyses from researchers in various fields, farmers, and associations. This meeting of perspectives associated with the diverse epistemic, normative and technical trajectories within these various groups constitutes an opportunity to reconnect the subject of biodiversity with social, scientific and political identities. During the research days organized with the support of MNHN, our purpose was to create the space for different actors’ intentions and points of view to emerge, analyzing the practices, knowledge and visions of and around crop diversity deployed in each context.

10Our hope is for this collection of texts to highlight the existence of multiple sources of maize crop diversity. Each article analyses different factors that explain the presence of heterogenous maize varieties in farmers’ fields. We will see the founding elements of the diversity of Mexican maize in the work of over two million farmers using seeds that they bred themselves, and who cultivate over half of the eight million hectares dedicated each year to maize cultivation (Lazos & Chauvet 2011, Perales 2017). We will also see, in France, in a completely different situation (notably within associative networks such as AgroBio Périgord), that there too farmers have implemented a system that generates maize diversity.

11The importance of maize in peasant agriculture in Mexico is presented first by Rafael Ortega Paczka, agronomist and representative of the Red Patrimonio Biocultural de México (Biocultural Heritage Network of Mexico). He specifically analyzes the historical and technical trajectory of maize breeding in Mexico through the prism of different epistemologies, where scientific and peasant knowledge blend together. His experience highlights farmers’ crucial role in efforts to improve maize in Mexico, encouraging participatory approaches. He takes as a model what is known as “Selección Masal Visual Estratificada (SMVE)” (stratified visual massal selection), describing how it creates a dialogue between the respective forms of ecological knowledge of farmers and breeders.

13Jean Foyer and Marianna Fenzi combining multiple conceptual and empirical resources from the sociology of public policy to explore the issue of conservation. To do so they examine studying institutional policy instruments, and the associated mobilization and implementation of various types of knowledge, within the Programa de Conservación de Maíz Criollo (PROMAC). They show how these different types of knowledge are mobilized—or, on the contrary, marginalized—in aim of making an object (maize conservation) governable. They catalogue the various forces that have shaped the implementation of the program, from the definition of its goal at the level of national institutions to its implementation at the local level.

14The text of Quatzalcoatl Orozco-Ramírez and Brush explores the role of culture in agricultural landscapes. In particular, they present the influence of local languages in the management of maize diversity. In Oaxaca, the Mixtecs and Chatines share the same ecosystem, but are distinguished by cultural particularities, including language. These particularities constitute lines of demarcation between the two peoples, so that, for instance, although they may be neighbors, they do not share the same seed lots. Behind the names given to local varieties lie the knowledge and practices transmitted in each language, whose subtleties may be difficult or impossible to translate. This case study highlights the forces that constitute bi-cultural diversity in the region, and shows how they can influence the evolutionary dynamics of this crop.

16The final contribution is that of the AgroBio Périgord association, which, along with the Muséum National d’Histoire Natuelle, hosted the exchange days that made this special issue possible. The article narrates the historical and technical trajectory of this program of networking of knowledge and practices on maize in France. In a homogenous varietal context, as in the European case, the adoption of heterogenous varieties has made an important contribution to the development of diversified agricultural systems. Farmers’ need to have their own seed thus reflects their concern with investing in more autonomous models, shaped by new forms of socialization around crop diversity in Europe (Fenzi & Couix 2021). Although their context differs from those in Mexico, these farmers share struggles in the aim of ensuring that crop diversity is valued.

17We thought it would be useful to complete this special issue on the management of maize diversity in Mexico with two documents related to the activities of the Museum's eco-anthropology laboratory. During the last six years, the researchers and students of this laboratory have carried out field studies in Mexico, which allowed them to gather collections of objects. Many of these objects are related to maize and its place in Mexican agriculture, food and daily life. We offer in the appendix of this issue, resulting from the 2014 meetings, a catalog of 72 objects related to maize in agriculture. A selection of these objects had been presented in an exhibition realized in 2019 with the Cultural Institute of Mexico in Paris; we describe it in this issue of the Revue d'Ethnoécologie.

18In conclusion, this issue seeks to highlight the interest of acknowledging the central role played by smallholder agriculture: in Mexico, central in terms of demography, total production, and cultivated area. Most previous research in this field has emphasized the consequences of the agro-industrial model and the erosion of crop biodiversity. In this issue, we focus instead on demonstrating the scale of the diversity and evolution of maize. This adaptive and dynamic diversity reflects great resilience, in the face of an institutional context that neglects it when it does not directly affect it. Although Mexican farmers work de facto on maize conservation in their fields, it seems essential that their practices be supported by the revitalization of conservation strategies on a cross-disciplinary basis, considering a diversity of actors. The contributions in this issue have the merit of encouraging reflection on the culture and cultivation of maize in Mexico in the hopes that it can finally be considered, not as a residual space that can serve as a “gene reservoir”, but as a social and ecological space that is fully active in its own right—one that is crucial for the country’s agricultural future.

Many people contributed to this issue. We would like to thank the authors for their participation and their tenacious engagement with this project all the way through. We would also like to thank the Action Thématique du Muséum (ATM): Savoirs naturalistes, expertise et politiques de la biodiversité, the Red Patrimonio Biocultural of Mexico, the AgroBio Périgord association and the Future Food Initiative for supporting the events in 2014 and the production of this issue. Finally, we would like to express our gratitude to the team of the Revue d'Ethnoécologie and to the translators who made this publication possible: María Auxiliadora Alcivar, Françoise Aubaile, Meriene Betancourt, Mathilde Bognon, Jacqueline Ferreras, Stephanie Hamard, Catherine Hoare, Vanessa Lopez, Sebastien Plutniak, Irene Pochetti, and Paul Reeve. Finally, we express our gratitude to the entire team of the journal Etnobiología, and in particular to Eduardo Corona, Arturo Argueta and José Blancas for encouraging the exchanges that have made this publication possible.