milpas and maize

" a milpa is a field, usually, but not always, recently cleared, in which farmers plant a dozen crops at once, including squash and beans, multiple varieties of squash and bean, melon, tomatoes, chilis, sweet potato, jicama ( a tuber ), amaranth ( a grain plant), and mucuna ( a tropical legume)."
from 1491 by charles c. mann

i have read quite a bit about the idea of intercropping and using plants to enhance soil fertility ( hence the whole cowpea/ winter wheat experiment) and the idea of growing the traditional mesoamerican triad of beans, maize, and squash appeals to m e so i have ordered organic, non-gm seeds and i am scouting locations out back and on campus for additional plants...my problem is squirrels...i grew maize on campus without incident last season ( it's on the right in the photo...northern tepehuam teosinte is in front of the cardboard i put in to help it stand out from the wheat grass) but the squirrels nailed all the maize in my yard...they waited until it was nearly ripe and gnawed the stalks off at ground level and obliterated my harvest...about what i expected but it doesn't bode well for a traditional milpa...so i have been in contact with various anthropologists whose work involves mesoamerican agriculture about a suitable substitute...i'd thought of teosinte, but northern tepehuan is an iffy proposition...and while i grew a bunch of zea diploperennis it doesn't really get big until august and the whole idea of maize is to provide a natural trellis for the beans to vine on( that and to help balance the nutritional value of the diet)...so i have been searching for a suitable substitute for my back yard...if i cannot use maize i at least want to keep it limited to a plant native to or domesticated in the hemisphere...two leap to mind, both from the same family...jerusalem artichokes get to be eight to ten feet tall and i have a multitude planted out back and i have a store buried from which i could seed more...but they are very bushy and produce rather a large patch of shade in their vicinity ( in fact there are no weed problems with them...they are so dense and produce so much shade no weeds can germinate anywhere near them ) which could be an issue...sunflowers pose no such problem for plants growing beneath them...the beans could germinate and the squash should have plenty of sunshine..so that is what i believe will stand in for maize here at home...i will try teosinte as well just to see what happens and keep things in the family so to speak...more stuff to grow and eat...more ways to get in touch with a culture...more to learn.