The Amer-indians traditionally grew corn, squash and beans together. People who have looked more deeply into it have noted that it is a very efficient use of a limited space. The beans climb the corn and squash uses the space in between rows. The combination seems to be more resistant to insects. The combination is also nutritionally complete.

They had several thousand years to get it right. Considering that they science and experimentation was an unknown concept, and they had no way of precisely measuring small improvements it is quite remarkable the progress they made.