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.
Santa Maria, Ilocos Sur
The land is quite fertile, most of which is irrigated; thanks to the zeal of Fr. Juan Cardaño, present (1850) parish priest who, with the help of the colonial government was able to realize any improvements of the town, including the construction of the irrigation system, after six years of work. In 1804, when Cardaño took over the parish, the harvest were always in the danger of being lost due to the lack of irrigation, thus only 994 tributes (were paid); now 1850, 2,595 do so.