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.
San José Mogote
Crop productivity may have seen an increase at San José Mogote due to the initiation of two simple irrigation techniques: Pot irrigation and Irrigation ditches. Pot irrigation involved digging many shallow wells in order to accumulate water, and then scooping up that water to use on surrounding plants. Irrigation ditches were small-scale systems used to tap into streams in order to allow water to flow over the plants.