Will the milpa become just maize? Diversity and management of maize, bean, and squash polycultures in southern Mexico

Arguably the most famous traditional polyculture is the interplanting of maize, beans, and squash characteristic of Native American agriculture and the Mesoamerican milpa.  What may be less widely appreciated is the level of detail at which farmers combine different landraces of these three crops to meet specific ecological, agronomic, and economic objectives.  Drawing primarily on a case study from Yucatan, Mexico, I document the landrace diversity present in milpa polycultures and describe their management by Mayan farmers.  I also assess prospects for the persistence of traditional maize, bean and squash polycultures in the face of problematic trends in milpa, such as reduced fallow periods and the widespread use of herbicides.  I find that Mayan farmers continue to be surprisingly resilient in adapting and modifying their cultivation techniques to maintain beans and squash in association with their staple maize crops—a sign of the enduring importance of milpa in rural Mesoamerica.