Crop and non-crop productivity in a traditional maize agroecosystem of the highland of Mexico

BACKGROUND: In Mexico, the traditional maize cultivation system has resisted intensification attempts for many decades in some areas, even in some well-connected regions of the temperate highlands. We suggest that this is due to economics. METHODS: The total useful biomass of several fields in Nanacamilpa, Tlaxcala, are evaluated for productivity and costs. RESULTS: Maize grain production is low (1.5 t ha(-1)) and does not cover costs. However, maize stover demands a relatively high price. If it included, a profit is possible (about 110 US $ ha(-1)). We show that non-crop production (weeds for food and forage) potentially has a higher value than the crop. It is only partially used, as there are constraints on animal husbandry, but it diversifies production and plays a role as a back-up system in case of crop failure. CONCLUSION: The diversified system described is economically rational under current conditions and labor costs. It is also stable, low-input and ecologically benign, and should be recognized as an important example of integrated agriculture, though some improvements could be investigated.