There's more to this question than people are thinking.
I'm starting to think the real answer isn't a large farm. Even at 30,000 acres, it wouldn't be the 'best' or even the 'largest' permaculture system.
Generally this is considered a faux pas in Texas, but I'm going to tell y'all for the sake of putting my cards on the table - my family has a >5k ranch in the Texas hill country. The last real offer on it was $60,000,000, the last high offer was 80, but it's not really for sale - my grandpa, who may be quite more stubborn even than Cassie's dad, likes to take offers just to imagine the money, but we've had it since I think 1938. It has its own natural springs, caves, miles of roads, hunting camp, two large stone houses, smaller houses. Sounds like paradise, right? See the website my brother made for it years ago - pipecreekranch.com/ We've got lakes, one with a concrete dam, ridge roads, the works.
It's been the cause of some very nasty fights, one that split my father and his sister apart - they don't talk - and my grandfather (96, turns 97 next month) hasn't helped but threw fuel on the feuding fire. It's been, in my opinion, basically mis-managed since white men set foot on the land in the 1840s, as has much of the hill country. It was once prairie, with the Comanche riding around on our land, and through Bandera Pass, the Lupan Apache. The settlers, as one (now deceased) old-timer JB Edwards told me, were so terrified of the Comanche that they let the trees grow right up to the house before they'd allow anyone to so much as chop a branch off. Now areas are unnaturally overrun with junipers - locally called 'cedars' - whereas they once clustered on the hilltops. In the 1930s, a government grant paid for JB and his brother to drag a massive several-ton chain between two bulldozers. One as far up as he dared drive it on the hillside, one down in the valley -- everything taken down. You can still see the massive scars on the mountainsides. It also seems to have semi-plowed, in effect, all the topsoil. At any rate, the land seems to hold less water and be very flood-prone. Another recent government program let us pay a Mexican to drive a Bobcat all day with a tree-cutter, to cut the junipers down individually, then pile them up and burn them. Another government program paid for British Petroleum ("BP") solar panels to be installed, to pump well water over to various water troughs along the ridge. But without much grass growing in the drought, there's not many cattle the ranch can support, so they're only rarely used. The politics of who-does-what are rather convoluted, but basically it doesn't matter because no one in the family has both the work ethic and the knowledge base to manage it well.
All of which is why, despite working on farms in Massachusetts (Morning Glory, Edgarton) and Ohio (Foxhollow, Mt Vernon), and getting an Environmental Studies Minor at Kenyon College, and making a documentary film on agriculture including interviews at The Land Institute in Kansas, an organic farm in California, and with fishermen and professors in southern Louisiana, and taking Geoff Lawton's PDC last spring and building a permaculture aquaponics system at my house and designing a plan for an acre plot here in Dallas, I've not even touched this ranch with a 10-ft pole, until yesterday.
Because yesterday I saw Gabe Brown's talk in Idaho last fall, and just couldn't help myself. As far as convincing my own family of the merits of permaculture, I think a moral argument, or any form of discussion that could take aim at how they do things presently, would be met with quickly shut ears and perhaps hurt feelings. They already all read "Holistic Management" by Alan Savory back in the 1990s, and nothing really changed. The only way that might work is to slowly feed them very feel-good videos. But I haven't really been doing that even. Probably the only thing that would work, and I think Cassie and anyone else who has to share land with others might try this, is to ask for your own manageable-sized plot of land to experiment on.
But let's say I / you / anyone convinces them - and there's often a "them" with large properties, say they're convinced completely, exactly as you could dream it, and set up a massive, profitable, permaculture-based operation. It seems anytime you give people something and say, "OK, share this," it's going to fail. As Geoff Lawton said, living and working with other people is very very hard - making, say, an 'intentional community' work is very hard. Even when they're all monks in a monastery, as two of my friends are, there's still massive drama and power struggles and people who cannot stand each other. Family is a crucible for this - it's a particularly tight-nit community who all have each other's strings-to-pull down by heart, at the ready.
Any profit venture is like making a movie. It's best when there's one director. Owning and operating land makes one the director, producer, and lead actor. No wonder my grandfather enjoys it, even at 96, with only in-name concessions of control to his (more easily controlled) daughter. And if she were in his position, I suspect it'd be the same. I've enjoyed shows like "The Men Who Made America." It's fun to say you know rich and famous people. I know several indeed. But it tears people apart, isolates them from the most valuable asset, which in my opinion is human bonds. Our family was mostly happy before my father and his sister began to see the possibility of owning / controlling this land.
So. What is the best large scale permaculture system?
Larry Santoyo's Los Angeles.
Happiness is having skills that fit you like a glove, living in abundance without chronic worries, surrounded by people you naturally agree with, working on a vision with your own hands that is out of love for those you've built bonds with.
Unhappiness is having contrived or coerced skills that fit someone else's bill, living in want and worry, surrounded by people that handicap or undercut you, working on meaningless projects with delegated hands that are done out of fear of losing control and power.
I know a dot-com San Francisco millionaire who's about my age, early 30s. He came up with the game "Mafia Wars," and owns properties around that city. The guy seems mentally unstable and severely isolated. He's a big preacher of entrepreneurship. He's pale and hard to reach.
I know Erykah Badu, who has multiple children by as many fathers, has one house (won't say where, she has stalkers) that is home to many people who seem to endlessly cycle through - her mother lives there, relatives, her entourage, Andre 3000, friends. She works hard but supports an ecosystem, and it sustains and nourishes her. She doesn't love to travel, so she does a lot of shows in Dallas and is a master of local promotion. She's gotten Dave Chappelle to come to her, and do local shows. The woman is as happy as a clam, and seems 15 years younger than her age.
Make a whole city like that, where things network into each other, where a supplier always is responding to an existing need, where enterprises are stacked and human bonds are formed naturally, a web of real skills, and you create stability in what economists call the 'informal economy,' which is nourishment. Geoff Lawton's ranch is the entire world, and he's always invited where he steps foot. As for what may happen with my family's ranch, I don't know. But it's not worth fighting over - my priority's not the plans or projects or profit, but the relationships. If something good comes of that, great.
Just my opinion anyhow.
