Agriculture in the prehistoric Southwest
After the Hohokam disappeared, Spanish explorers of the 16th century noted the use of canal irrigation in only two areas of the Southwest: eastern Sonora, primarily practiced by the Opata and Lower Pima, and among the Pueblos of northern New Mexico. Irrigation by the Opata and Pueblos had different objectives. In Sonora, with a long growing season, two crops of maize a year were grown in river valleys. The spring crop during the dry season was dependent upon irrigation; the summer and fall crop during the rainy season utilized irrigation to supplement rainfall. The necessity of irrigation probably required a high level of social organization. In New Mexico, with only one crop of maize per year possible, irrigation was supplemental and the lesser dependence on irrigation implies less social organization than in Sonora.
History of the potato
In the Altiplano, potatoes provided the principal energy source for the Inca Empire, its predecessors, and its Spanish successor. Andean Indians prepared their potatoes in a variety of ways, such as mashed, baked boiled, and stewed in ways similar to modern day Europeans. The Andean Indians also prepared a dish called papas secas, which was a process that involved boiling, peeling, and chopping. These potatoes were then fermented in order to create toqosh: and ground to a pulp, soaked, and filtered into a starch referred to as almidón de papa. However, the cash crop of the Andean people was chuño: created by letting potatoes freeze overnight, then allowing them to thaw in the morning. Doing this repeatedly allowed for a softening of the potatoes. Farmers then extract the water from the potato, leaving it much lighter and smaller. This new creation was then prepared into a stew, and usually was an addition to a stew. The benefits of chuño are plentiful. Its primary benefit is that it can be stored for years without refrigeration, which came into use especially during years of famine or bad harvests. Secondly, this long shelf life allowed it to be the staple food for the Inca Armies, due to how well it traveled and maintained its flavor and longevity. The Spanish fed chuño to the silver miners who produced vast wealth in the 16th century for the Spanish government.