Farms in Oaxaca, Mexico have survived political strife, storms, droughts, and floods, but many were particularly affected by the 1994 North American Free Trade Agreement. After they were forced to compete with Canadian and American agribusiness, many of Oaxaca’s farmers failed to adapt in time and abandoned farming altogether, fleeing to Mexico’s cities or further north to the United States. Surviving farms embraced more labor-efficient monoculture operations to compete. Now researchers argue that NAFTA and monocropping not only propelled Oaxaca’s rural exodus, but also lowered nutrition in the region. To get its nutritional self-sufficiency back, they say, Oaxaca should revive the Mexican tradition of “milpa” farming.
But what is milpa? The word is derived from an indigenous Mesoamerican language and refers to a traditional method of intercropping. Writing for Cornell University’s Alliance for Science, Luis A. Ventura-Martinez describes how smallholder farmers in Mexico relied on milpa farming for centuries to produce a variety of foods for markets, domestic animals, and their families, interspersing rows of corn with herbs, beans, and peppers, among other produce. “It is a system where the different species coexist, sharing resources like water, light, soil, and even ecological interactions, such as the nitrogen fixation provided by the beans,” as he explains it.
Only a small percentage of Mexico’s farmers still predominantly practice milpa farming, so Mexican, Argentine, and Dutch scientists recently collaborated on a study to determine what these farmers were missing out on by gradually abandoning “La milpa.” Armed with a grant from CGIAR, the team zeroed in on two communities in Oaxaca, San Cristobal Amoltepec and Santa Catarina Tayata, to investigate how out-migration from Oaxaca has impacted food security in the region and how the rise of monocropping impacted regional nutrition. Through surveys, census data, and satellite imagery the team of scientists put these two rural farming villages under a microscope, with particular focus on the vitamin content of foods grown on single-crop farms (only maize or only beans) versus more traditional milpa farms. Writing in PLOS ONE, the researchers say there is a clear distinction.
“The milpa produced more volume of food per area compared to the other systems,” they reported. “The milpa also produced all the nutrients and vitamins (except for B12) required to feed at least two persons [per hectare].” Oaxaca’s single-crop farms may be more profitable in the face of free trade agreements, but they fall short in nutritional diversity, according to this study. The researchers conclude that out-migration from Oaxaca pushed more farms into monocropping systems as labor became harder to come by. Oaxaca’s farmers themselves seem to know what they are missing by moving away from milpa farming, but they have good reasons to continue the trend. “The milpa has lower labor self-sufficiency when compared to sole maize,” the team admits. “Farmers in the area showed that they understood that the milpa could produce more food volume but they argued that it required a high degree of labor.”
Reviving milpa farming may be a great way to improve the nutritional variety of Oaxaca’s produce. But the farmers themselves won’t take this leap until someone figures out a way for them to grow multiple crops on milpa farms in much less labor-intensive ways. It’s a challenge ripe for creative thinking and agricultural innovation.