Permaculture as a Solution?

There's an outfit in the Midwest which is pushing "permaculture"--the idea if we could convert from annual crops to perennials we'd save on expenses for fuel, etc. and be more friendly to the environment.   I mention this because this Extension post on cotton includes this:

"A defining characteristic of cotton growth and development is that it is a perennial plant. Being a perennial plant means that it flowers and sets fruit over a long period of time. In its native habitat, or with adequate warmth, cotton would not die in the fall. Perennial plants also flower and produce seed as a secondary mechanism, as opposed to vegetative growth. Because cotton lint is produced from the seed coat, it is the essential challenge of cotton production to overcome the perennial nature of the plant. Nearly everything we do to manage a cotton crop is in response to its perennial nature in an attempt to produce seed and lint in an annual row crop environment."

 I've expressed my doubts about permaculture before, but with global warming the frost line will move north and we won't have to plant cotton every year. (In the Rio Grande valley they speak of "stub cotton", cotton which is growing from previous year plantings.)

Permaculture Makes the Times

Some quotes from the Times article:

"Yet in recent years, Mr. Mollison’s ideas seem to have bubbled up from underground, into the mainstream. “I just trained the Oklahoma National Guard,” Mr. Pittman said. “If that’s any kind of benchmark.” The troops, he said, plan to apply permaculture to farming and infrastructure projects in rural Afghanistan.

This “guild” of complementary plants is the opposite of annual row-crop agriculture, with its dead or degraded soil and its constant demand for labor and fertilizer. Permaculture landscapes, which mimic the ecology of the area, are meant to be vertical, dense and self-perpetuating. Once the work of the original planting is done, Mr. Mollison jokes in one of his videos, “the designer turns into the recliner.

At the lowest level of a food forest, then, are subterranean crops like sweet potatoes and carrots. On the floor of the landscape, mushrooms can grow on felled logs or wood chips. Herbs go on the next level, along with “delicious black cap raspberries,” Ms. Joseph said.
Other shrubs, like inkberry, winterberry and elderberry, are attractive to butterflies and birds. They’re an integral part of the system, too.

Ruling the forest’s heights are the 40 large pin oaks already in the park, whose abundance of acorns will make a banquet for squirrels."

Some comments:

• blackberries require work, just as any cultivar does.  In particular you have to fight weeds and prune the canes.  That's from personal experience.
• also from personal experience: I've nothing against pin oaks; I've got one by my house.  But I can testify along with acorns for the squirrels, it provides lots of shade.  Hostas and impatiens do well, but I wouldn't try growing vegetables under it.  I've never tried carrots or sweet potatoes and I wouldn't; I don't want to waste my effort.
• the idea of layering carrots, with herbs above, then raspberries is ridiculous, IMHO. 
• permaculture does offer advantages--less erosion, but the productivity from a unit of area is going to be much less than intensive gardening, whether one uses organic methods or not.  
• the bottom line: there's no free lunch, ever since we left the Garden of Eden you always have tradeoffs.