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.
Zia people
In New Mexico, rain was scarce during certain parts of the year, so new techniques of farming were developed (such as dry farming and crop rotation) The Zia would plant seeds in a fertile piece of land close to a river or stream. They would then dig paths to the fields from the stream, and thus the water flowed from the stream to water the crops. By strategically placing rocks in the paths, they controlled the flow of water to their crops.