<P> Agriculture in the prehistoric Southwest describes the agricultural practices of the Native Americans inhabiting the American Southwest, which includes the states of Arizona and New Mexico plus portions of surrounding states and neighboring Mexico . Maize (corn) was the dominant crop . Introduced from Mesoamerica, it was first cultivated in the Southwest about 2100 BCE . Sedentary cultures based on farming developed afterwards including the Hohokam, Mogollon, Ancestral Puebloans, and Patayan . Due to a deficiency in precipitation throughout the region, irrigation and several techniques of water harvesting and conservation were essential for successful agriculture . </P> <P> Although it is possible that Indians grew several native plants such as gourds and chenopods at very early dates, the first evidence of maize cultivation in the Southwest dates from about 2100 BCE . Small, primitive maize cobs have been found at five different sites in New Mexico and Arizona . The climatic range of the sites is wide as they range from the Tucson basin in the Arizona desert, at an elevation of 700 m (2300 ft), to a rocky cave on the Colorado plateau at 2200 m (7200 ft). That suggests that the primitive maize they grew was already adapted to being grown in both hot and dry and short - season climates . </P>

The growth and success of the american southwest depended on