Closed System Edible Landscape

Hello, all.  This is my first post, and I'm hoping you all wouldn't mind to help me with my permaculture design.  I've read about Biointensive farming, Edible Landscapes, and Low maintenance Food Forests, and I would like to combine them together.
I am starting to search for a property to move out of my apartment, but I don't know

How much space will I need?
What should I grow?
Is it even possible to live entirely off of Perennial Garden food with very little daily maintenance?
If I want lots of protein in my diet, but don't want to keep animals, am I mostly just growing soybeans and peanuts?

Thank you so much to anyone who will help!

Using Biointensive, with a good climate, long growing season, and plenty of rain or irrigation, 4000 square feet per person is the minimum amount of land needed to grow a nearly complete vegan diet.  So approximately .5 hectare could ideally feed 10 people, but this is very optimistic I think.  Also, Biointensive is not a low-maintenance method of food-growing, it's meant to be the most sustainable method for growing the most food in the smallest area.  For a low-maintenance food forest or other perennial-based system I would personally not want less than 1 acre, and if in a cold or dry climate, double that.  But this is just based on my own observations in my own yard.  Places with good growing conditions can probably get by with less.  And of course it all depends on what you want and what you can afford.  People often purchase more land than they can care for (I did) but, on the other hand, some people feel it is impossible to own too much land!

Before we can attempt to help with this we need FAR more information.

What climate [temperatures, latitude, precipitation quantity and seasonal attern, winds....] type of soil and landbase are you working with?

Do you have access to irrogation to establish systems or are we bootstrapping on rainfall?

Thanks for all replies.  I live in zone 9b in the southern US.  There will be lots of rainfall.

Do you think 1-acre-per-person is required for a food forest?
I'm thinking sweet potatoes for Ground cover/High Calorie Root Crop, but I don't see how any of the Biointensive "Carbon-Calorie" crops fit into a food forest 7 layer schema.
What perennials do you think have the highest protein yield?

Biointensive is primarily based on annuals, so you'll need to pick different crops for a food forest.  You mentioned Biointensive so I thought maybe you would be using that system for at least part of the diet.  I guess not?

I'm not convinced you can get "lots" of protein from a vegan diet.  

In your zone you should look into David Goodman, he's on these boards and has an awesome youtube channel.

Here's David's website:   http://www.thesurvivalgardener.com/

I will point out that your sweet potatoes also have edible leaves. For a green, they are very high in protein. So long as you get a variety of foods you will be getting all the necessary amino acids for your body to build complete proteins. It doesn't have to come from any one food. That said see what the Huffington Post has to say about avocados http://www.huffingtonpost.com/2015/08/26/avocado-health-facts-didnt-dont-know_n_3786419.html

Welcome to Permies, Yousif!  I tossed you your first apple, as that is a great initial post/idea.  It seems from what you wrote, that you are somewhat new to the topic of food forestry and bio-intensive, so I think that you have found a great resource in coming to permies.com.  By continuing to create threads, ask questions, and give information about exactly what you want to do, we can best help you.  Your zone is a very productive place, with a lot of species that could fit your needs, so you are very fortunate!

Here are my thoughts.  If you have the money to buy a good sized chunk of land do it, but concentrate your efforts on a very small area or areas.  Get your food forest plans established, but use bio-intensive systems to get your food production, and your soils established quickly while your perennials establish in the same area or beds.  Bio-intensive is usually done with annuals, but there is no reason why the methods can not be adapted to including perennials in the system.  Expand bio-intensively, slowly, and slowly add perennials, and continue the process outwards from your original smaller area.  

First let me say, I've never tried living off of just perennials. So what I have to add to the conversation comes from my experience growing a combination of perennials and annuals as my food source. I personally believe in diversity. I also believe in networking with people in my community, thus trading my excess for items I don't raise myself. This way I can add fish, beef, milk, cheese, bread, and a number of veggies & fruits that I don't grow on my own homestead.

How much space? Even if you live in zone 9 and get plenty of rain, it depends upon what you intend to grow. Some crops require a lot more square footage than others. Trees aren't nearly as productive per square foot as annual crops. My own approach to "how much" was to purchase as much acerage that I could afford, then start a garden & orchard, then keep adding until I was producing enough. I found that the annuals garden didn't have to be as big as I thought but the orchard space needed to be tripled from my original plans. But since I started adding permaculture methods to the farm, ncluding polyculture, now my orchard space could be reduced if I wanted to. This....my current "gardens" are about an acre total or a bit more, and my orchards about another acre. Since I'm planning on adding grain crops, I'm anticipating adding an acre of assorted grains, but I'm looking into incorporating them in with some of the orchard area. (My growing areas are spread out, so it's hard to say if they are an acre exactly without actually using a tape measure to calculate the space.)

What to grow? What you like to eat. While sweet potatoes produce abundant greens, if you won't eat them it makes little sense to grow them. In my own garden, I can grow potatoes extremely easily, but hubby and I don't eat much of them ourselves. But luckily they are a popular trading item. But we do like green beans, tomatoes, broccoli, cabbage and more, so I grow that. Plus on the perennial list, I grow bananas, pineapples, tangerines, and papayas for ourselves. Other fruit trees and fruits, mamaki, moringa, pipinola, various herbs, and mints produce more than we need, thus go mostly for trading.

Live entirely off a perennial garden? If one had enough land, I suppose one could. But it would lack diversity, for sure. Most of what we eat consists of annuals, not perennials. But perennials make an important contribution to our overall diet. Plus, most of my perennials don't produce harvestable food year around.

Very little daily maintenance? Gee, every new gardener who attends my teaching sessions asks that within the first month. They want to grow lots of food with little or no work. Personally, I don't see that happening. Farming and/or growing all of one's food takes work. Now, if one wishes to live off of just acorns and sweet potato greens, then the work will be minimal, but there is still some work involved. Having said this, I find on my own farm that the more acreage I have in perennial polyculture, the less work I put into it per square foot. The growing is not as intensive, thus doesn't need as much intensive attention. But it also means that I need to spend more time walking, hauling compost and mulch around, and that sort of thing. Thus I've traded intensive physical digging in a tight garden space for lots of walking and hauling across acres.

Bio-intensive is labor intensive. Not that you'd spend all day working, but it isn't what I'd term low maintenance. And besides, it's a system designed for annuals.

For what it's worth, I normally work 17 hours a week on what I call "playing with my food". These are jobs that I take great pleasure in doing and includes tending livestock, greenhouse work, garden work, irrigating where needed, harvesting. That doesn't include my time spent processing compost, mowing, creating & working on hugelkuktur pits and other projects, fixing and maintaining equipment, foraging, trading my excess, processing my harvest. These latter are my afternoon jobs which get mixed in with house construction, general farm maintenance, shopping, off farm appointments, meetings, volunteer work, and the myriad of other things I do.

I think a perennial diet could be diverse, as there are many perennial edible plants.  It would be different from what most people are used to eating, but it could be more diverse than what most people eat.  Here is a list of perennial vegetables for hot humid climate:

http://perennialvegetables.org/perennial-vegetables-for-each-climate-type/hot-and-humid/

Lots of great links and advice, all. Thank you.

Maybe self-sustaining and high-yield are mutually exclusive. I'm probably just naive and unrealistic...or lazy.
But my vision is basically a suburban garden of eden.
Walk out into my yard and just pick dinner from the trees and bushes right outside my house. Maybe pull up a tuber and some leeks.
Leave town for a couple weeks, and come back to find everything still in good, productive order. And with HOA-friendly curb appeal, if possible.

I'm willing to put in lots of work up front for this. I'd prefer not to need more than an acre or so.

One of the hugelculture articles on richsoil says something about self-seeding annuals. Maybe that's a better way to go than perennials.

I don't think one has to choose between annuals and perennials.  I think ideally one would have both.  I think your vision is ambitious but by no means unrealistic, especially in your climate.

Producing a variety of lower maintenance foods in a suburban garden is quite doable. Perchance starting out just supplementing your diet this way is a good start. Then gradually increase the percentage of homegrown as you acquire experience and success. I started out slow and eventually worked up to producing over 90% of my own food. (Actually I could attain 98% but I enjoy eating out two meals a week with friends.)

Many annuals can be grown in such a garden, because once they are established and heavily mulched, they don't need intense attention. The idea would be to time the plantings so that there is a staggered harvest so that everything doesn't come time for harvesting all at once. And choosing varieties with long harvest windows would be an option too. Avoid varieties that are described as concentrated set. Instead look for ones described as long window for harvest, repeat harvest,  or long standing in the field. Potatoes. Beans. Peas. Carrots. Beets. Tomatoes. And more could be options. Include a selection of herbs because they can give variety to the same old veggies and make it seem like something new.

Try new veggies and fruits. Too often I find people reluctant to try something they haven't eaten before. Chayote produces not only squash-like fruits, but the vine tips make nice greens, and the root can also be eaten. In shady areas try okinawan spinach, turmeric, and ginger. These need very little attention. Chaya can be used as a privacy hedge and it's edible, needs very little care. Various taros are easy to grow and could be used for their leaves and stems or later harvest for the corms. Chocolate mint and low herbs can be used to shade soils where mulching isn't desired. Yes, mint will spread into your lawn but it sure makes mowing smell nice! There's lots of other things out there you could experiment with that are either perennials or low maintenance once established & mulched.

I think what you're intending to do is GREAT! Even if you only achieve 50% of your food, that's a marvelous accomplishment. 50% is like-- wow! Along the way on your food journey you will learn what doesn't work in your system and what does. If it doesn't work, then you'll need to decide just how badly you want that fruit or veggie and decide if you're willing to put the extra work into it. In my own garden I currently don't think it's worth the added effort to produce summer squash or slicing tomatoes. (Too many pests and diseases) And up until recently I didn't bother with lettuce and other fresh-use greens. But just this year I've decided to create a system for greens. Yes, it's finally worth the extra work.

I'm in zone 9b-Florida. We get a substantial amount of yearly rainfall, but most of it comes in the middle of summer. Hot, humid Florida summer doesn't equal good gardening. Our best growing season is late fall through early spring. I can't count 10 days I've seen rain since mid October. I'm just venturing into the world of permaculture, but have grown vegetables for the last 4 years. Very steep learning curve in the sandy soil here.

My successes have been pigeon peas, Florida cranberry Roselle, moringa, hot peppers, callaloo-Jamaican amaranth grown for its greens, cow peas, okra, kale, chard, lettuce, kohlrabi, mustard, collards, carrots, turnips, beets, radish, beans, sweet potatoes and peas. I've had limited success with tomatoes, eggplant, cukes, squash and melons. It has taken 4 years to get the soil built up to where it isn't constant work. I'm sure someone with a bigger budget could get it done faster. Composting in place in raised beds has done the most good.

Right now we are harvesting around 70 percent of our veggie intake, but we are also meat eaters.

Good Luck on your new venture. We don't have enough land for a food forest so that would be on my wish list if starting over. Lots of fruit trees to choose from in this zone if you have the room.

Pigeon peas are nitrogen fixers and last several years. You can eat the green pods or allow to dry. Moringa will freeze to the ground, but come back. I'm experimenting with amaranth (for seeds), Malabar spinach and ground cherries this spring.

I agree with others who mentioned David the Good. He has a couple good books specific to Florida gardening.

Yousif Quadir wrote:If I want lots of protein in my diet, but don't want to keep animals, am I mostly just growing soybeans and peanuts?

Soybeans  - 28.5 g per 1 cup serving;
Navy Beans - 16 g per 1 cup serving;
Pinto Beans  - 15.41 g per 1 cup serving;  
Dried Lentils -  13 g per 1/4 cup serving;
Quinoa -  8 g per 1 cup serving;
Peanuts - 6.7 g per 35, dry roasted without salt;
Almonds - 5.9 g per 22 almonds;
Pistachios -  5.9 g per 49, dry roasted without salt;
Walnuts - 4.3 g per 14 halves;

@Su Ba, how do you mean that established annuals can require so little attention? Do you just mean that you can leave them to seed their own surrounding soil from dropped fruit?

@Kristi Anglen, Can you harvest Kale all year? What kind of yield per area are you getting?

David the Good is definitely pro-perennial. He has an article about fruit trees being the secret to high yield/low maintenance that is right up my alley. But I understand that fruit trees in general are not great yield per area.
What sort of edible fruit tree+vine combinations might go good together here in florida?

I'm thinking of doing a Square Foot Hugel/PolyCulture experiment. Take a small container (1-3ft maybe?) and plant a miniature food forest using edible companion plants.
Examples,
Container1)Leeks + Tomato + Sweet Pepper + Broccoli + Basil + Oregano + Sunflower in a container with a bunch of woody compost underneath a thin layer of dirt and mulch.
Container2) Strawberries + Blueberries + PassionFruit + Thyme (+clover? What non-legume, edible nitrogen fixer might go here?)
Container3)Banana + Winged Beans + Avocado + Sweet Potato + Okra + Squash (summer or winter? How do I choose?)

Any thoughts on this idea? If this works, could I transplant this mini food forest into the ground and expect it to expand across the yard?

Yes I have had some kale plants last through the summer. This year I purposefully planted some in a partially shaded area of my garden to see if I can get a decent harvest from them year-round. They say you can do that with collards as well, but I haven't tried that yet. I put 1 kale plant per square foot, but I'm thinking I could fit 2 in a square and will be trying that next year. I did plant herbs and carrots in between plants which worked. Chard could also possibly be something if given a little shade could go quite awhile since it is like kale and you cut the outer leaves and they grow new ones.

Anybody have any experience with Breadfruit trees? Wikipedia says they are "one of the highest-yielding food plants."
What makes something a "Carbon Calorie Crop" in the Biointensive method? Why are Corn, Rice, Wheat etc. in that category?
Does anyone think Collards might be a good substitute for Kale or Spinach? Collards seem to grow better/easier/more productively than those other two and have similar nutrition profiles, yes?

Those crops, in addition to providing calories, produce a lot of straw which is made into compost, adding carbon to the soil.  In How to Grow More Vegetables by John Jeavons, the Biointensive manual, there are pages of crops listed by their different functions.  Some calorie crops, the root vegetables, are not considered carbon crops because they don't produce sufficient organic material, but they are important to grow because they produce a lot of calories in a small amount of space.   http://www.growbiointensive.org/Self_Teaching_7.html


I think Collards are one of the best crops one can grow in a warm climate - they contain a lot of nutrients and are more heat tolerant than Kale and Spinach.

Breadfruit trees don't survive anywhere in the continental USA, according to the book Perennial Vegetables. You'd have to be in the Florida Keys or Hawaii.

If the role of grains in Biointensive is to grow your own compost, how does a food forest provide its own compost? Specifically, a perennial food forest without animal waste cycling in a place where leaves don't routinely Fall to the ground? If nitrogen fixers bring N directly into the soil, is there any way for other crops to do that with carbon?

If Collards or Kale are planted only once, will they self-propagate? What about tomatoes or other annuals and biennials?
Can these be incorporated into a >High-Yield, Self-Sustaining Food Forest< ? (That maybe is a better name for this thread...)

That's disappointing about the breadfruit trees. Jakfruit and Maya Breadnut are both Breadfruit relatives that seem to grow here. But the yield on them is way less.

In tropical environments the soil actually tends to be very low in organic matter because it breaks down faster than it's replenished. My understanding is that the health of the plants relies much more on a healthy soil biome supported by root exudites.

Basically the plants form symbiotic relationships with the fungus and bacteria in the soil. The plants produce food that attracts and multiplies the species that break down what organic matter there is as well as directly mining minerals from teh rocks. These bacteria and fungi multiply because of the easy food from the plants make the essential nutrients available directly in the plants' root zone. It's a whole ecosystem following the practices of nitrogen fixing plants, except they don't form nodules to hold the micro-organisms they're supporting.

Adding organic matter is still helpful in these circumstances, but it tends to be short lived. Between the soil organisms and the growing plants the materials are quickly absorbed into the living plants. It may be closer to slow release fertilizer than a long term soil conditioner. With that in mind doing things like burying whole trees (the shear amount of carbon will take a while to chew through) and building earthworks to (capture and hold water long enough for the plants to absorb it even when there isn't a high carbon soil) is paramount.

Can anyone correct me where I've gone wrong? I'm not an expert, I just tend to incidentally absorb a lot of trivia. That doesn't mean I have a complete understanding, so I appreciate any corrections anyone can offer.

Oh, self seeding and perennializing plants, I have cilantro spread from one side of the yard to the other. I planted it two years ago and let it go to seed in a garden bed next to the fence. I haven't planted it since.

Tomatoes fairly reliably come back if you let a fruit or two drop to the ground and decay in place.

I haven't had my kale go to seed, but by growing it in the summer shade I get several years per plant. I do hear good things from other people about how well it self seeds. I'm planning over the next two years (as they are biannuals) to let turnips, parsnips, and carrots go to seed in my garden. All of these have strong reputations as self seeders if you ever let them flower. The hard part will be the two years of preparing by not harvesting the plants.

I'm in Zone 8b and reliably have sweet potatoes come back from the bits of root I don't harvest, so they're a very sound perennial vegetable. Remember to harvest and eat the greens from it and you get even more benefit. It has an unusually fine taste for a leafy green, not overpowering in any way.

As long as you don't have to have the bulb part of the onion there are many different options for perennial onions. I was really excited to see the canadian onions that Tyler sent me last year have self seeded. There's tiny onion plants all around the original planting.

Something you can search for to reduce your exterior input needs are seeds developed for subsistence farmers. They are chosen or developed for use by farmers who cannot afford to continually buy inputs for their farms. Often they're good varieties for growing your own seed. I think they idea is they're organic because of destitution, but it works very well for someone looking for a cleaner gardening style. My first exposure to these were carrots from Baker Creek seeds, they may carry more plants like these. I think all of Joseph Lofthouse's plants qualify. I think Tyler would be happy to provide links for her favorite seed companies. They carry native and traditional seeds that were developed before chemical farming even existed.

Casie Becker wrote:As long as you don't have to have the bulb part of the onion there are many different options for perennial onions.

Perennial onions have been the big winner for me here.  In addition to the Canada Onion you mention (our native wild Allium canadense) I have Walking (aka Egyptian) Onion, Perennial Leek (aka Elephant Garlic), and Garlic Chives.  These can all be harvested by cutting.  If white bulb part of the onion is needed, they can be cut further down the stem, and will grow back as long as the base and roots are left in the soil.  I haven't tested to see exactly how much needs to be left but I suspect it is only about one inch.

The walking onions and garlic chives are still doing well. The onions haven't started walking yet, though. I was hoping the leek had just gone dormant, but I can't tell if it was a garlic clove that sprouted this fall in that spot or the leek coming back. It looks identical to the garlic I have in another location.

The leeks usually come up with a thicker leaf than garlic.  Time will tell.

Are you familiar with permaculture concept of Zones? You have mentioned Biointensive method that is ideal for Zone 1, your garden close to the house, relatively small fenced area. Low maintenance food forest can be located further from the house, usually in Zone 2. Edible landscape can have many forms, from hedges formed out of edible plants, through alley cropping, to agroforestry in zone 3 or 4. I would advise you to look at big picture first.
There is a great guide about property purchase, by Geoff Lawton, please take a look: here
If you do not want to keep animals, you have to design the system where all human wastes are being composted (compost toilets) and returned to the system in order to keep soil fertility and building, as well as you need to reserve quite a large area for the plants that will be grown for mulch and/or compost.
The more species you include in your design, the more stable and fertile your system will be, and the more healthy your diet will be as well.

My interest in Biointensive comes from their claim that its the most food you can grow in a given area.

The High Calorie Root Crops (30% of Biointensive garden) include sweet potatoes, which grow like weeds in my area. As a bonus, they're easy to harvest and store.

For Nutrient-dense vegetebles (10% of garden), I can grow squash and turnip greens with little to no effort.

Winged beans and other bean varieties are high in protein and act as nitrogen fixers. So that category should be easy to fill as well (although health concerns about too much legume/soy-type protein mean I'd prefer a high-protein leafy green, root or fruit here instead.)

So, my only issue really is finding a Carbon-Calorie crop (60% of garden) with "grows like weeds" attributes. That way my Permaculture "Zone 1" can be treated like Unmanaged Brush and still yield dense, High Yield food!

Everything else above is described as self-perpetuating AND is commonly grown in suburban gardens. But I've never seen anybody grow corn, rice, or wheat in their front yard without upsetting the HOA.




Also, are these onion and garlic varieties you're discussing essentially interchangeable from a culinary perspective?

I don't have a very sensitive palate, but to me the onion varieties are interchangeable with any other green onions. The canada onion has a very strong flavor, but you control that by quantity when you cook.

It feels a bit wasteful not to eat it, but maybe amaranth would be a good carbon crop. The leaves are edible (and I think high protein for a green) but the older ones may be tought enough to be unpalatable. Grain varieties produce lovely flower heads full of easily harvested pseudo grains and then there's a thick stalk in the middle of all that that may be comparable to a traditional grain stalk for carbon. Many seed companies carry some of the grain varieties in their flower section because their such attractive plants. I spread my spent flower heads across my garden at the end of the season last year, so when warm weather arrives I'll find out how well it self seeds. Otherwise I'm replanting from saved seed.

edit: HOA's are vile. We grew popcorn in the front yard last year and I'll be planting sweet corn there this year.  This is an old subdivision from before HOA's became common.

I had great success one year with the Amaranth variety "Golden Giant" which makes a large attractive plant with a huge seed head.

What kind of yield did you get on your amaranth? I figure I need 550kg/year per person to meet my protein requirements.

What's its lifecycle like? Will the same plant produce comparable yields each year? Or does it have to be manually cut down each year and composted to make room for next year's seedlings?
(I was interested in perennial tree kale until I learned that it gets woody and inedible after only three years or so.)

I agree it seems wasteful to grow so much inedible carbon for compost. Only so much sunlight hits an area of land, it seems like it should all be used for making people food. Don't plants get most of their carbon from the air? Growing "carbon crops" doesn't seem like it would do anything to maintain the phosphorus, sulfur and trace minerals in the soil.

Even if I find a nice place without an HOA, I'd like to avoid lowering my neighbor's property values by growing corn in the front yard  Amaranth is pretty, though!

I didn't weigh mine, but that variety is supposed to produce up to 1 pound of seed per plant.  I got the seeds here: https://www.bountifulgardens.org/products/VAM-2010

It's an annual, so needs to be replanted or some allowed to self-seed.

The idea behind growing carbon crops in Biointensive is that sufficient compost/carbon must be added to keep from depleting the soil.  The Biointensive website warns  "All of the components of this system must be used together for optimum effect and to avoid depleting the soil."   http://www.growbiointensive.org/grow_main.html

I think you misunderstood me. It feels like a waste to grow food that you don't eat, so unless you find the leaves unpalatable I wouldn't see you burying the whole plant. Carbon in the soil doesn't feed the plants. It feeds the soil biology. It builds soil structure which helps maintain healthy soil moisture. The soil microorganisms, fed by the carbon, mine other nutrients for the plants as well as help fight off pathogens.

Ok, carbon in the soil isn't for the plants, its for the health of soil organisms and structural integrity. So, how does a perennial forest fulfill this function without an annual churning of grain-stalk compost?
Is this function entirely supplied by animal manure? (That doesn't seem right because manure is chemically and physically different from vegetable compost in biointensive carbon farming.)

And I don't see how this method protects from depleting the soil anyway because youre building up carbon over time, but depleting sulfur, phosphorus, and minerals. Diluting them, even, because the carbon fraction is increasing.
By contrast, a perennial like a tree with large roots grows to extract more minerals from farther and farther away over the years.

Hugelkultur addresses this by just burying decades worth of nutrients in the form of a tree trunk from the beginning.

Perennial forest soils are dominated by fungi. Mycelium thrives on fallen trees, branches and leaves. Forests create carbon surplus naturally, by absorbing CO2. Soil microbes are responsible for carbon sequestration in soils. The entire process is being run on energy of Sun. Fungi deliver minerals to roots and exchange them for carbohydrates.

Ok, so the Carbon-farmed inedible parts of wheat and corn take the place of fallen trees in a forest and the logs of wood in hugelkultur. All three serve to feed the fungi, which then release minerals from the surrounding rocks.

So, if my pre-gardening deep soil prep includes a large supply of woody and rocky matter, then you shouldn't need carbon-calorie crops for decades. Correct?

Composting annual crops every year vs. composting slowly-grown trees once or twice in a lifetime is essentially the same thing but with a different frequency.


Remember, my goal is to get the MOST nutrition out of the SMALLEST landscape with the LEAST >ongoing< work and cost.  (I accept that this may mean lots of work at the beginning.)

Priority #1: reduce the grocery bill toward zero. Priority #2: no ongoing labor once the system is in place.

Annual plants require soils dominated by bacteria, perennial plants prefer soils dominated by fungi. Annual plants usually require much more maintenance than perennial plants. In any case you have to return nutrients to the soil in order to keep it fertile. In perennial systems nature is doing that for you, more or less. In annual systems more inputs are required.

MOST nutrition out of the SMALLEST landscape with the LEAST >ongoing< work and cost.  

Sounds like food forest to me. You start with 90% of support species and 10% of  crop species, you speed up succession and after let's say 8 years you end up with 90% of crop species coming mostly from perrenials and 10% of support species. Such system will become mostly self sufficient and will produce more yields than annual monoculture. Also, "no ongoing work" is possible only in some climates, in cold climate for instance you have to do a lot of work to process your yields in summer/autumn in order to have food for winter.

Can the 90% support species be edible? Sweet potatoes are my mulch maker. Chives, thyme, and Jerusalem artichokes are edible insectary species. Vining beans are my nitrogen fixer. Plant my Jakfruit and mulberry or whatever highest-conceivable-yield climax trees. Feast on the other stuff while I wait for them to join in.

I've been assuming that subtropical florida is a good climate for "no ongoing work" but please correct me if that's not right.

And what area of land is needed for this type of system, per person? Biointensive claims 4000sq/ft per person. Can a food forest of high yield plants approach, match, or exceed that?

I think the "no ongoing work" would be a problem for the really small-space food forest, because especially in a warm climate, some plants will outgrow others if not pruned regularly.  So, smaller space if you can maintain it, much larger space if you won't maintain it.