Birol, Ekin; Villalba, Eric Rayn; Smale, Melinda - International Food Policy Research Institute (IFPRI) - 2007
"Maize, the second most globally important staple crop after wheat, originated in Mexico, where it is typically grown as part of a set of associated crops and practices called the milpa system. This ancient mode of production is practiced today in ways that vary by cultural context and...