2.3 People Per Acre

Relistening to one of the podcasts to help do a synopsis got me thinking. I went ahead and looked up the current population (I rounded up) and the noted land mass world-wide that is usable as land to farm on (their estimations likely remove areas that we permies know could be restored to usable land or that don't allow a tractor, but are still usable. make of this what you will.) According to math based on these numbers, I came up with a listing of 2 and 1/3 person per acre of usable land on the planet! Obviously, that number is probably closer to and even 2 or maybe even 1 if we start applying permaculture to city design, food forest parks in cities, better use of land, etc. Still, it makes you really think looking at the numbers. We need to kick it into high gear really soon since permaculture takes time to establish.

Anyway, just a random thought I had the last few days. I wish I had an estimate of land mass that noted the land that could be used by permaculture methods that isn't listed simply because it can't be used for modern monocrop production. I remember a video here where the couple mentioned that they didn't think the acre they had would produce enough for more than one person even at it's peak. I'd love to see people trying to break that record of production by a fair margin. Maybe set the bar at 1 1/2 people from one acre. If we met that bar, set the new bar as 2 people per acre.

Rosemary Morrow told my husband's PDC class that it was 1,5 hectares/person arable land. How she got that number I don't know.

The figure I see that is frequently used is 4.5 acres per human.


http://www.radicalsimplicity.org/footprint.html

I have seen quite a few statistics regarding this. A lot of variation in the numbers.
As mentioned, I'm certain that many acres, which are not counted, are suitable for some kind of production.

Perhaps one could not produce 1,000 bushels of wheat on it, but sheep or goats could make good use of the land.
One acre of prime land in Wisconsin might be sufficient for one dairy cow, while in some parts of Texas it is claimed that you need 25 acres per head.

Finding the most suitable use of any given piece of land is a key to finding out how many people any given acre can support.

I'm sure that most of those estimates do not include millions of acres that a permie could make productive.

I came to the number I had by taking the listed number of humans on earth atm (the number was going up even as I did the math, so that's why I rounded up) and divided it by the number of acres (had to convert from hectares) listed as the data taken most recently on such matters. I don't figure they counted a lot of usable land though, since Permaculture offers ways to make use of all sorts of land they would have left out of the numbers.

I would love to see Dawn's listed numbers be the right ones. That leaves a lot to work with. That would put it at almost 4 acres per person on the planet. Certainly enough to work with there.

I forge the exact numbers, but Geoff Lawton has stated we could feed the world with permaculture techniques using like 10% (less maybe) of land currently in production. This would produce less food but would be more nutrient dense. And of course you wouldn't be growing corn & soy to feed to animals.

The rest of that land should go back to wilderness.

Is it the urban homestead that feeds four adults on 1/10 of acre? So one acre could feed 40? Or 90% of their food at least, and they sell their surplus. That does not account for clothing etc. but it proves that you don't need that much room to feed people. They are vegetarian, but have goats and chickens for eggs and meat - and I mean our neighbor gives his male goats away because he doesn't want to feed them - so that would be sufficient to meat for most people right?

We have 1,5 ha per person here (2 kids and 2 grownups), and I think well be plenty able to provide most of our food from just the 2000 m2 (1/4 acre) around the house, and sell from that. So the rest is what we will sell and live off of, but once the house is payed (in two years), the solar panels payed (soon hopefully), and we have out own water... Well it won't be much that we need will it?

2000m2 = 1/2 acre sorry

Dawn Hoff wrote:Is it the urban homestead that feeds four adults on 1/10 of acre? So one acre could feed 40? Or 90% of their food at least, and they sell their surplus. That does not account for clothing etc. but it proves that you don't need that much room to feed people.

I'm familiar with the urban homestead you're talking about, and while I agree that it's an inspiring story, I would suggest that it doesn't prove you can feed four people on 1/10 of an acre. You'll note that they don't really tell you how they revitalize the plant nutrients in their soil over an extended period of time. This is a critical component of any sustainable food production system. To me, it seems like they're running an experiment about how many edible plants you can cram into a small space, not how much food you can produce on a sustainable basis without external nutrient or energy inputs.

That is true... to some extent: It does prove that you can produce that amount of food on that little land - so they are not using land outside suburbia to have their food produced (except for a bit of grain afaik), so the land not used could still go back to nature. No they don't say /how/ they do it - but they have a lot about "reduce, reuse and recycle", sustainable energy etc. So I imagine that they are trying at least to be sustainable, how sustainable that is, we don't know.

For starters, I envy you living in Spain.

I've been doing permaculture-like stuff for a few decades, and while I obviously believe in the power of some its basic principles, I also think there are certain tropes out there that are, at their core, more smoke and mirrors than practical sustainable food production techniques.

One trope is closed loop aquaponics in which fish manure allegedly produces crops. No small aquaponics system is self-sustaining and also produces a significant number of consumable calories. It takes a lot of electricity to power a small system (water and air pumps, heaters, lights, filters, etc.), and untreated fish manure is barely adequate (and often less than adequate) to grow low calorie foods like lettuce. Fish manure is not a complete nutrient for most crops and nowhere close for calorie dense veggies like tomatoes. Nevertheless, people are enamored of these small aquaponic systems because they create the illusion that you're operating a perfectly balanced little artificial ecosystem. The reality is far different.

Another trope is that 1/10 of an acre urban homestead. It's easy to get caught up in the beauty and productivity of that homestead without looking behind the curtain. Behind the curtain I'm pretty sure you'll find lots of fertilizer being brought in from outside to keep the operation going, and I doubt it really feeds a family everything they eat throughout the year. It's still an impressive display of productivity, but when you think about it so is the amount of corn grown on 1/10 of an acre in Iowa. Today, the average production on a 1/10 of an acre in Iowa is about 800 lb. of shelled corn or about 320,000 edible calories per 1/10 of an acre. That's enough to feed an adult for about six months.

George Hayduke wrote:For starters, I envy you living in Spain.

I've been doing permaculture-like stuff for a few decades, and while I obviously believe in the power of some its basic principles, I also think there are certain tropes out there that are, at their core, more smoke and mirrors than practical sustainable food production techniques.

One trope is closed loop aquaponics in which fish manure allegedly produces crops. No small aquaponics system is self-sustaining and also produces a significant number of consumable calories. It takes a lot of electricity to power a small system (water and air pumps, heaters, lights, filters, etc.), and untreated fish manure is barely adequate (and often less than adequate) to grow low calorie foods like lettuce. Fish manure is not a complete nutrient for most crops and nowhere close for calorie dense veggies like tomatoes. Nevertheless, people are enamored of these small aquaponic systems because they create the illusion that you're operating a perfectly balanced little artificial ecosystem. The reality is far different.

Another trope is that 1/10 of an acre urban homestead. It's easy to get caught up in the beauty and productivity of that homestead without looking behind the curtain. Behind the curtain I'm pretty sure you'll find lots of fertilizer being brought in from outside to keep the operation going, and I doubt it really feeds a family everything they eat throughout the year. It's still an impressive display of productivity, but when you think about it so is the amount of corn grown on 1/10 of an acre in Iowa. Today, the average production on a 1/10 of an acre in Iowa is about 800 lb. of shelled corn or about 320,000 edible calories per 1/10 of an acre. That's enough to feed an adult for about six months.

And I love living in Spain.

That is certainly true - and I agree with the aquaponics critique. Since they don't write permaculture anywhere - and since their garden looks suspiciously orderly (rows and rows of veggies), I don't think they are doing permaculture - and yet I do think they are doing some companion planting etc. My point wasn't that it was sustainable, but that they were doing it on very little space.

Damn straight. It is an impressive amount of veggies they drag out of a small suburban yard.

I guess you've heard the controversy about them trademarking the term "urban homesteading"? Kind of a sharp corporate maneuver for simple people of the earth.

George Hayduke wrote:Damn straight. It is an impressive amount of veggies they drag out of a small suburban yard.

I guess you've heard the controversy about them trademarking the term "urban homesteading"? Kind of a sharp corporate maneuver for simple people of the earth.

Oh my! Just lost so much respect there! No didn't hear - as you've noticed, I don't live in the states.

I guess you've heard the controversy about them trademarking the term "urban homesteading"? Kind of a sharp corporate maneuver for simple people of the earth.

Yeah. Right after they trademarked the term, their attorney began contacting dozens of web sites that were using the term. They were told to remove every mention of the word. Caused quite a controversy. As I recall, there was a site that had been using the term for several years, who refused to edit it out of their content.

During world war two, England had a dramatic rise in vegetable production as every plot was put into productive use. But that only lasted during the rationing.

I would be really surprised, if you were able to get every Joe and Jean to start succesful gardening, keeping poultry, beehives and tending to some fruit trees. There is an enormous amount of knowledge we have lost and must re-learn if we are to move to a more sustainable food system.

I took Spain's history data, showing that on average, there were 2ha (1/2 5 acre) worked per person before the green revolution. This use includes meat, fibers, wood, medicines, cut flowers. We also had a strong fishery tradition which, we could say, reduced the need for cultivated food. Foraging and game did exist, but I don't think it made a difference.
Work was hard and people were poor.

With modern ecological techniques I don't expect people working less hard and being richer, once the fossil fuels era is gone, but maybe we can support a bigger population than back then.

In case of emergency, efforts can be directed towards food production, but this cannot last since eventually we will need to replace our clothes, new furnitures, restock on herbs and booze, tools, a source of lighting, etc.

2 hectares = 20,000 square metres = approx 5 acres

D Logan, Everyone,

The 2.3 people per acre figure is very interesting!  And I especially appreciate the added note that it probably does not include areas that Permies might find useful but general Ag doesn’t.

When I was doing my masters research on energy and the environment, I came across an interesting fact/trend.  In many areas of the 3rd or 4th world (that’s an imperfect term, define as you wish), small farming villages on especially fertile ground are especially prone to disappearing and the land turning back into wild ground precisely because the ground’s fertility enabled its inhabitants to lead a more prosperous life which ironically encouraged them to leave the farming village and seek a more wealthy life (again, define as you will) in an urbanized area.  Since there was no younger generation to continue the village, the village would die out (but not the people).
The point here is that there probably is more fertile land out there that was arable not long ago and could be arable again but at present has reforested or otherwise gone wild.

I just found this an interesting point I thought I would add.

Eric

Interesting question, this! The thing I wonder, though, is how wise it is to put up fixed boundaries between "agricultural land" and "nature"? Sure, I get that a non-intensively managed forest garden or "tended wilderness" necessarily produces much fewer (human-useable) calories per hectare than a corn field, but on the other hand it does so without significant detrimental effects for local biodiversity. I'm wondering if it wouldn't be more in line with permaculture ethics to try to gently integrate ourselves and the things we eat in the wider ecosystem, rather than say "This land is ours, we decide what's here. That land over there is Nature, and we don't go there." We are part of the ecosystem, after all, and I wonder if our trying to put boundaries in place is what led to monocropping chemical agriculture in the first place.

Of course it would probably be hard or impossible to feed the number of humans now in existence solely through forest gardening and similar techniques, but I did read somewhere that the American prairies once supported more bison (counted by weight) than the American corn fields and feedlots at present support cattle... I'm not saying it's necessarily possible or desirable to let those boundaries go all at once, just that it's something that might be worth thinking about.

Sorry if this was a tad off-topic, it just occurred to me.

Eino, I agree that we should be able to grow food not just on open fields. But in Scandinavia, the growth season is short and most edibles need light. I have a mushroom plot in the forested part of my farm, also some berry bushes like blackberry. But fruit does not ripen or veggies grow in the shade of trees. Might be different in warmer and sunnier climates.
Chicken, goats and lamb like dappled shade and find lots to forage under the trees. My farm at 10 acres is too small to support even one cow.

source


source

Anne Miller posted the comparison between a football field and and acre. I can remember seeing a presentation about a place described as a "Black College" where the Leadership decided that the football program was costing far too much money for the benefit to the average students. They turned their football field into a farm. They used the produce in their cafeterias and sold some at affordable prices to the neighborhood. They encouraged students to provide some of the labor and gave them "pay" as credit against their course fees.
Not being a football fan, I thought this made economic sense in a very healthy way!

Jay, that is a great story.

Football is a terribly expensive sport.  I am pretty sure that all the injuries get billed to the school.  There is the cost of the whole coaching staff, the price of the stadium and its upkeep.  My school used to irrigate the practice field with a huge center-pivot sprinkler attached to a fire hydrant!  I always wondered how many dollars were in the air at any one moment when it was in operation.  There are numerous other costs that I can’t even conceptualize.

Turning that are into a garden where students can earn credit is a wonderful idea!!

Great story!!

Eric

A very interesting concept. But 8 year old information in today's world is quite out of date. I wonder what current numbers would look like.

And because I will be facing the feeding of approximately 10 people on 40 acres of hilltops and hollers in western West Virginia, the numbers that would apply to that scenario must certainly be very different! I don't think there's much more than maybe 2 acres of flat land, and so I will be learning about and implementing growing that food supply in different ways. Terracing might be one of the ways to increase the amount of space, but it's also land with a forest on it! This might be what brought me to Permies to begin with. Creating a "food forest" among the trees already there, and clearing some of the less steep parts for an orchard to be planted like a food forest, using what I've learned here.

Even at the 2.3 people per acre, if I can use all the acreage, that's a bit over 17 people. But do these numbers include the animals for food, fiber and/or other beneficial uses (think manure and ?)?

I know this went a bit off topic. I am still interested in what current numbers look like, partly because I'm seeing news stories about both how "Mr Microsoft" has purchased 1000's of acres of farmland, and "vegetable farms" on the waters of the world producing 1000's of pounds of food daily!

Kaarina Kreus wrote:Eino, I agree that we should be able to grow food not just on open fields. But in Scandinavia, the growth season is short and most edibles need light. I have a mushroom plot in the forested part of my farm, also some berry bushes like blackberry. But fruit does not ripen or veggies grow in the shade of trees. Might be different in warmer and sunnier climates.
Chicken, goats and lamb like dappled shade and find lots to forage under the trees. My farm at 10 acres is too small to support even one cow.

I'm very well aware of the problem, since I also live in Scandinavia (northern Sweden, will move to mid-Norway). I suppose I was thinking more about the very clear division between "cultivated land" and "nature", and to me it feels a bit like that division implies that we are somehow not part of nature. I was thinking more in philosophical terms than in immediately practical, and used forest gardening only as an example (though there are many others) of less intensive land use. That said, I do think there are a lot of possibilities for forest gardening even in Scandinavia, although there is certainly a reason for the historically heavy emphasis on animal food in this region. But I suppose all this is a topic for a separate thread...