If you are growing corn that way then perhaps you can grow it in that same corn-beans-squash plot each year. You wont be able to stake out the exact spot where each corn plant was......And put beans exactly there the next year. Just hoe the soil around and mix it
You use the old cornstalk as a bean pole?
The beans and the corn are supposed to grow together with the beans using the corn as a support. The nitrogen in the beans won’t be available the first year, but it should remain in the soil for the second year. If I change the mounds (the sqaush is in a separate mound)the second year, it will be like year 1 all over again unless I mix t all up. I know that I will have to add lots of extra stuff to keep this all growing. It is an Indian method; I might even throw a fish in there! :)