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.
Chok people
The Chok were a "purely agricultural people, cultivating millet and eleusine grain grown in the cold air of the summit and possibly a little tobacco." The "millet [was] grown on the fertile and well watered flats at the base of the Elgeyo escarpment, and [was] watered by means of irrigation, while eleusine grain (was) grown high upon the hill sides and was dependent on rain". The irrigation system as Beech noted, "is most ingenious, and it's original construction must have required a vast amount of toil and patience".