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.
Huarpe
Huarpe people settled in permanent villages beginning in the 5th century CE. About 50 to 100 people lived in a village, making them smaller than Diaguita settlements. They were agrarian people who grew corn ("Zea mays"), beans, squash, and quinoa ("Chenopodium quinoa"). Towards the 15th century, Huarpe territory expanded into the current Argentinian provinces of San Luis, Mendoza and San Juan and even on the north of the Neuquen Province. They inhabited between the Jáchal River at north, to the Diamante River at south and between the Andes and Conlara Valley on San Luis.
They were never fully part of the Incan Empire, but were influenced by Inca culture and adopted llama ranching and the Quechua language after 1480.