Would you like to write a synopsis of the arguments for us please, Dave.
I'll give a synopsis Aunty.
Quite a sweet film, good subject. Basically, the previously ridiculed permaculture is coming back into fashion ....well in a sense .... I don't think it's back in favour with those that dominate farming. Some good points made, but overly laboured to stretch it out. A peak oil derived logic. Stop tilling and destroying soil structure, grow those foods and varieties that don't need pesticides and fertilisers..... many more perennials.
Speaking as an old permaculture person, I would say permaculture well suits the small holding in an holistic economic sense, and of course even big farms for the time being until they can be redistributed into smaller units to give the micro bio-diversity needed for it to function fruitfully in a food sense. The film made the point we would need a small change in eating tastes, but that can be easily achieved. One specific point made was less meat, more nuts ... and many more trees/hedging that can be used as forage.... I'm into that one.
One other excellent point re iterated in the film that relates directly to us allotment/small garden growers ....our food productivity per square metre has long been 5 times that the best modern mass agriculture can muster, although grains and wheat in particular are a separate issue. How many hours we put in is another matter though
Permaculture is a very difficult thing to do well on a small allotment surrounded by others who don't grow in the same way, so self sustaining organic growing is well more productive in my experience in the small spaces we have to grow in. Not only that, most landlords won't allow trees/animals etc.
So, to precis, permaculture MIGHT be the future ( if only ). Bless her, she's young. She hasn't the faintest idea how strong the forces are she's taking on, and of course, the whole thing would need massive land reform.
She touched on the NPK theory as just one theory. NPK came from the post war era with industries with their production lines and surplus product. Good film .. but too many shots of dreamy romantic cows and bees ... photographically it could have been a Tesco promo. Perhaps new young film makers are all GM cloned these days.