Ultimate low maintenance unirrigated annual calorie production while the food forest establishes?

Hi all! I wanted to add this as an edit to my first post on dry gardening, but then I realized that I can't edit the post (or, at least, I couldn't find the button for it.) So, I'm sorry for creating a new thread for this, I just didn't want this to get lost in the great discussion over there.

One of the major focuses of my study over the past few years has been in increasing the efficiency of dry farming/gardening on a home/homestead scale. This year I set out to design a bed that could, in addition to a dozen chickens, provide all of one's calories for an entire year without irrigating and with a minimal footprint. The point was to create a system that, once set up and planted, you could completely walk away from to go install food forest on your property knowing that that system would provide you with enough calories to eat in the meantime.

I don't have yield data yet, but so far this bed has performed better than expected. The growth is lush and green with no signs of moisture stress. The corn is tillering readily, which is a sign that it has the moisture and nutrition it needs to support the extra growth. I have not had to irrigate (and couldn't if I wanted to, on account of not having a functioning well-pump at the moment), and the lack of irrigation has meant that few new weeds have been able to germinate, though I have had to pull a few of the more pernicious perennial weeds, like Canada Thistle. All-in-all, I would estimate that I've spent less than 10 minutes a week weeding this bed, and expect to do less as my living mulch establishes.

I wanted this bed to accommodate the number of seeds provided in a typical packet of seeds from most suppliers, while also growing enough plants that one could save seeds for successive generations without inducing inbreeding depression. To that end, it accommodates just over 200 corn plants. You would need to save beans from an earlier season, or buy them in bulk, in order to completely fill out this bed, but since beans are self-pollinating and relatively carefree, that is an easy proposition.

I have set up two such beds this year to support the two of us that are currently living on the site. I don't expect them to 100% meet my goals this year due to our lack of compost, the (expected) incomplete germination, and our unseasonably cool weather, but I'm excited to see how close it gets in a "worst case scenario". Over the following years, the calories produced by these beds will sustain us as we develop the food forest on the property. As the food forest itself begins to produce more calories, these beds will allow us to add additional members to our co-op. I will be adding at least two more of these beds so that I can rotate through a crop of sunflowers and amaranth as well. In a suburban setting where yard sizes won't support multiple beds, that may be as simple as teaming up with neighbors and rotating through your crops so each household is growing a different crop each year.

Here's a deep dive I did on the design considerations and set up of these beds:  

I hope you guys enjoy it, get some inspiration from it, and come back to me with all of your questions and feedback. I'm still trying to figure out additional climbing and trailing crops I can grow with my rotations of sunflower and amaranth. I'm considering noodle beans and loofah with the sunflowers, though I'm worried that the two types of beans may harbor the same pests/diseases, and loofahs are not supposed to work well in my climate. Ideally I'm looking for things that would primarily be harvested at the end of the season after drying/reaching maturity, since the idea is that you won't be entering the bed once it's established, except to harvest all at once.

I'm real curious how you come out on the 500 sq ft concept. I've seen and read about that before but I myself (I think) have yet to come anywhere close to producing enough food for two people in that space. Also is the 500 sq ft the total of the area or just that part in actual production? My two fenced gardens, if you subtract the space devoted to paths, comes to not quite 2000 sq ft of growing area. Granted some of that is wasted each year, in a sense, since things like melons and sweet corn are really more of a treat than food.

I am pretty happy with my gardens and we always put up quite a bit for winter use along with the fresh stuff we eat but I'm rethinking some things now, mostly because of the revelation I got from the discussions on calories. Now that I think about it I guess the melons and sweet corn do count as part of the yearly calorie needs. Still I imagine those calories that can be stored up for the off season are the most important. I might make an effort this year to track exactly h0w many storable calories are produced in how much space.

Mark Reed wrote:I'm real curious how you come out on the 500 sq ft concept. I've seen and read about that before but I myself (I think) have yet to come anywhere close to producing enough food for two people in that space. Also is the 500 sq ft the total of the area or just that part in actual production?

It's 500 sq. ft. per person, to clarify, and not 500 sq. ft. for 2 people... in case I accidentally gave that impression.

I'm gonna have to redo the math on the fly and see if it still checks out. It's been long enough now that I don't remember exactly how I came to those specific numbers, and I've revised my estimates for things like squash seed yields since then, so I suspect that it'll fall short by a bit. Let's see...

2,000 calories a day x 365 days = 730,000 calories per year per person
280 eggs per chicken per year x 12 chickens x 80 calories per egg = 268,800 calories from eggs per year

That leaves 461,200 calories left to produce in 500 sq. ft.

It's a 9x9 grid with 41 spaces growing 5 corn plants each with an approximate yield of .25 pounds. My actually yield was about .23 pounds per plant, but my best producers were just over .30 pounds per plant, and those are the ones I save seed from.

205 corn x .25 pounds x 1657 calories per pound = 84,921 calories from corn  (some sources list higher calorie counts for corn, which I probably used initially when doing the math, but this lower number is the one I decided on for the calculator)

That leaves us with a balance of 376,279 calories.

There are 40 remaining spaces which contain one winter squash apiece. Steve Solomon lists the yield for climate appropriate (maximas where maximas do well, moschatas where moschatas do well, etc.) winter squash, grown without irrigation, at 20 pounds per plant (and 50 pounds for plants that are fertigated with 5 gallons of liquid fertilizer every 3 weeks or so during dry periods.)

40 squash x 20 pounds per plant x 182 calories per pound = 145,600 calories from squash

Of course, not all of the squash is flesh. I think I originally wildly underestimated that a squash was 80% flesh and overestimated that a squash was 20% seeds and refuse by weight. When I weighed the few example squash that I used to come up with my numbers for the calculator, I ended up a figure of 88.6% flesh and 4.6% seeds, with the remaining bits as refuse. This was a small sample size with smaller squash. I'm sure the numbers with vary with larger squashes.

145,600 x 88.6% = 129,002 actual calories from squash flesh

And then...

40 squash x 20 pounds per plant x 4.6% from seeds x 2538 calories per pound from seeds = 93,398 calories from squash seeds (I know that my initial estimate was way higher than this, so that's probably what's gonna to make the numbers fall short.)

Accounting for squash, we're now at a balance of 153,879.

I looked at growing 2 to 4 beans per corn stalk, and I don't remember which number I landed on. We need to hit 154k calories, so let's see if either of those numbers gets us there.

2 beans x 205 corn x .25 pounds per bean plant x 1575 calories per pound = 161,438 calories from beans

Which puts us almost 10,000 calories over our target.

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So, the question becomes, are those yields actually possible in this configuration? My plan was the weigh my yields and see how close I got, but our entire region had a bad year for cucurbits. I yielded 0 squash, summer or winter (as well as 0 cucumbers.) It was weird. I've never had a year that I didn't have more zucchini than I knew what to do with. The only squash that yielded at all in our region, because of the especially cool and wet season we had, were the small kabocha types, which I didn't grow. I had lots of deer browse and bean mosaic virus... some of my beans regrew after the deer ate them down, but none of them had time to mature beans before our first frost. I yielded 0 beans. And out of 205 corn seeds planted (because I didn't have enough seed to overseed), I had a roughly 75% germination rate, and then lost a majority of the ears to deer as well (though, the corn was happy and tillering readily before the deer got a hold of it, which tells me there was at least sufficient moisture and fertility for the corn.) Corn was the only thing that wasn't a total loss, but I only yielded about 60 ears from about 154 plants and 205 seeds. So, basically, I have no data that's good for anything.

The amount of space needed varies based on rainfall. In really dry areas, you'd have to go much larger to get the same estimated yields from the same number of plants. 500 sq. ft. isn't going to cut it there. This particular size and arrangement puts the corn on 18-inch centers and squash on 5ft. centers, relative to each other. This is theoretically enough space to get the estimated yields when these crops are grown in isolation; I'm not sure if it's enough when grown as a polyculture. Then there are questions about soil fertility, amount of rainfall, etc. In heavy clay with minimal or non-existant organic matter, with no compost, and with minimal mulch... everything was stacked against this design this past season.

I won't be able to repeat the experiment this year because of disease pressure, and I don't plan on making any more of these beds until I know that the numbers actually work out in the real world. It takes me about 6 days to make one of these beds with hand tools in our heavy clay, and I don't have 6 days to spare this year. This year I'm thinking I'll use the bed for amaranth (which, by all accounts, could easily outperform the corn), possibly with melons. That's assuming I can clear out the weeds that have filled in the space over winter... I'm contemplating using controlled burning to clear the weeds from this bed, but don't have a more specific game plan than that. Next year, or the year after, I want to repeat the experiment and see if I can get proper yield data. Hopefully at that point I'll be able to properly compost and mulch the bed, and that'll further help reduce moisture stress. Ultimately I'm thinking that the squash are going to want at least an extra three feet between them to yield well without irrigation, and even the corn might want extra space given the competition from the beans. Until I actually have yield data, I won't know what I want to tweak and how. Corn looks like it will yield as expected in this configuration if I can keep the wildlife away from it. Squash and beans are still a big question mark.

Yea, I figured the 500 sq ft was per person, still I have approximately 2000 sq ft actual growing area not counting some others outside the fences that I hope may work for such things as sorghum and amaranth. Actually I'll find a spot inside for some sorghum but between what I got from seed companies and what I bought bulk at the market I have jillions of amaranth seeds. If it is anything close to being as "weedy" as I'm told, I am hopeful I can just broadcast it a number of places and some of it might grow. Still I'll probably tend at least a little of it till I see how it does.

I never considered calories from the chickens, which I currently have none of. I've had them off and on over the years and have mixed feelings about them. I do miss our own fresh eggs but the are a pain to take care of in my opinion. I have never been able to raise all their own food even in summer, partly because they are so destructive if allowed to free range in the yard and gardens. And we have quite a population of hawks and other critters. I'm thinking if I get back into poultry it might be ducks or maybe quail. Ducks according to Carol Deppe are far less destructive and better at controlling insect pests.  Although it might be tough to get eggs, wild turkeys can, with some patience be semi-tamed, enough so to bring them in easy range of a 22. Not gonna get more than one or two though before the tame quickly wears off the rest. Quail I think might be fairly easily raised in a chicken tractor type set up and from what I understand are fairly good layers.

Anyway, I was thinking of striving to produce all the necessary calories from the garden, not even including in the calculations those things such as grapes and especially pecans that grow here and there on their own. I guess I'll see how it goes this year.

Oh yeah. My main garden is 4,000 sq. ft. (2,800 sq. ft. excluding the paths.) It's mostly for proper vegetables and not calorie crops, though I'm including some stuff that's experimental and I'm growing in smaller quantities. Then I have two checkerboard beds, which add another 1,000 sq. ft. On the east side of the barn there's probably another 2,000 sq. ft. where I'm putting some pull sprouts from store bought potatoes. On the south side I mostly have perennials, but I'm going to put in a secondary corn patch this year for my actual seed crop... that's probably another 1,500 sq. ft. Then I have the "fields". The west field is where I'm conducting my squash breeding project. I'd guess that it's 20,000 sq. ft., but I haven't measured it and I'm terrible at eye-balling area. It might be closer to 30 or 40k (I worked in a 30k sq. ft. nursery, and I'm thinking they're probably close to the same size.) Then there's the east field, which is where my potato breeding project is going. The area that's "prepared" so far is probably about the same area as the squash field, maybe less, but there's room to expand as needed.

So yeah. A lot more than 500 sq. ft. Granted, it's unirrigated and managed with hand tools, so foot-for-foot it'll be less productive than a tightly managed, irrigated, small, urban garden. I'm only expecting a pound per plant on average from my Peruvian potato seed, though that might be an overestimate given that an unknown percentage of them just won't produce tubers at all. Squash I'm dubious about. Last year was a bad squash year and if that continues, then the example I have is that only the smallest varieties will actually produce. I'm throwing a broad mix of genetics in the ground. If it's a good squash year I'm expecting almost 4,000 pounds of squash (which is almost enough calories to feed two people... though I'd think that'd be a pretty miserable diet if that's all you were eating.) It's a lot. When I last ran the numbers I figured I was growing enough for about 4 people if I got okay yields without crop losses. But I'm working on the assumption that it's going to be another bad year and I'm going to lose most of it, and at the end of the day I need to make sure I have enough to feed myself after accounting for losses. I'm actually expanding quite a bit over my initial numbers thanks to the seeds I've been gifted... as long as I'm able to get everything in the ground. My contour planting technique is speeding up the planting for a lot of the bulk stuff. Ultimately I have about 15 mouths to feed, but this year my only obligation is to feed myself, anything else is extra. If I can grow enough to feed a couple of friends and their kid, then they can justify moving out here to help manage things, so that's the medium term goal.

So... we're looking at like an acre and a half so far? I'm ultimately planting trees in most of this area, and I'll continue to grow annuals for as long as they get enough light. I've already got a few young, disconnected patches of food forest that I'm expanding as I can snag cuttings and divisions of things, but outside of the main garden I don't really delineate between annual and perennial spaces. I figure the plan is to produce calories from annuals until the perennials fill and the space and produce enough calories to replace them, and then continue that leap-frogging from annuals to perennials as I need to feed more people. We'll see.

Oh, and on the subject of chickens, check out Karl Hammer and Paul Gautschi's systems (basically the same system at different scales.) I know Carol prefers ducks, but chickens are integral to my fertility management. I'm not quite where they are yet, but they at least provide the example of it being done.

Yea the fertilizer they make is another big drawback to not having chickens. My coop, which is not conveniently located and currently covered in weeds is built to produce fertilizer. The roost area is open to the outside on three sides from the ground up to about 4 feet. Above that is the enclosed roost. It is fenced off form the chicken yard so they can't get under the roost, they access up a ladder from the yard side. Under the roosts is a bottom of chain link and chicken wire, so critters can't get to them but the poop falls through. It's easy for me to just throw weeds, leaves or whatever under the roost to get all mixed up with the manure and then to rake it back up to use in the garden.  If a possum or something want's to go under there and help stir the manure and weeds together in an attempt to dig under the fence, they can have at it.

If I get chickens again I'm going to tear that coop down and rebuild it sharing a fence with the garden so it is more convenient for me. Ducks don't roost up high of course but I don't see why some modification of this set up might not work with them too.