There is no such thing as historical truth. There are differences in the way Indians see themselves and the way Western historians see them. However, almost all families plant corn, beans, squash, and watermelon. They tend to have 2-3 small plots, and diversify planting strategies to cope with flash floods that can wipe out a plot. Corn is not very important economically speaking, but it continues to be important as a religious symbol.
Corn is essential to maintaining the integrity of religious practice.
Even Hopi s who live off the reservation at least nominally participate in the planting, raising, and harvesting of corn. It represents a religious duty. It is a part of oral tradition. Anything that speaks, has meaning, and can communicate and idea is a part of oral tradition. Fields are fertilized through the trampling of corn stalks into the soil from season to season.