Milpa is a crop-growing system used throughout Mesoamerica. It has been most extensively described in the Yucatán peninsula area of Mexico. The word milpa is a Mexican Spanish term meaning "field", and is derived from the Nahuatl word phrase mil-pa "to the field" (Nahuatl mil-li "field" + -pa "towards"). Based on the ancient agricultural methods of Maya peoples and other Mesoamerican people, milpa agriculture produces maize, beans, and squash. The milpa cycle calls for 2 years of cultivation and eight years of letting the area lie fallow. Agronomists point out that the system is designed to create relatively large yields of food crops without the use of artificial pesticides or fertilizers, and they point out that while it is self-sustaining at current levels of consumption, there is a danger that at more intensive levels of cultivation the milpa system can become unsustainable.
The word is also used for a small field, especially in Mexico or Central America, that is cleared from the jungle, cropped for a few seasons, and then abandoned for a fresh clearing. In the states of Jalisco, Michoacán, and other areas of central Mexico, the term milpa simply means a single corn plant (milpas for plural).
Charles C. Mann described milpa agriculture as follows, in 1491: New Revelations of the Americas Before Columbus (New York: Knopf, 2005, pp. 197–198):
"A milpa is a field, usually but not always recently cleared, in which farmers plant a dozen crops at once including maize, avocados, multiple varieties of squash and bean, melon, tomatoes, chilis, sweet potato, jícama, amaranth, and mucana.... Milpa crops are nutritionally and environmentally complementary. Maize lacks the amino acids lysine and tryptophan, which the body needs to make proteins and niacin;.... Beans have both lysine and tryptophan.... Squashes, for their part, provide an array of vitamins; avocados, fats. The milpa, in the estimation of H. Garrison Wilkes, a maize researcher at the University of Massachusetts in Boston, "is one of the most successful human inventions ever created."
The concept of milpa is a sociocultural construct rather than simply a system of agriculture. It involves complex interactions and relationships between farmers, as well as distinct personal relationships with both the crops and land. For example, it has been noted that "the making of milpa is the central, most sacred act, one which binds together the family, the community, the universe...[it] forms the core institution of Indian society in Mesoamerica and its religious and social importance often appear to exceed its nutritional and economic importance."
Milpitas, California derives its name from the term "milpa".
See also 
- Agriculture in Mesoamerica
- Domesticated plants of Mesoamerica
- La Milpa
- Forest gardening
- Inga alley cropping
- Maya diet and subsistence
- Terra preta
- Three Sisters (agriculture)
- Chapulín de la milpa (Sphenarium purpurascens), a grasshoppers species found in Mexico and Guatemala
- Controlled burn
- Crop rotation
- Shifting cultivation
- Nigh, R. (1976) Evolutionary ecology of Maya agriculture in highland Chipas, Mexico. PhD dissertation, Stanford University. Ann Arbor: University microfilms.