3 ms·

I don't know what the maximum number of people you could sustain on an acre is, but my guess is way less than 1000. Like an order of magnitude less, perhaps clo

I don't know what the maximum number of people you could sustain on an acre is, but my guess is way less than 1000. Like an order of magnitude less, perhaps closer to two orders less. The world record corn yield is 500 bu/ac. 1 bushel of corn is about 1500 calories. EDIT: 1500*56=84,000 calories If you could do 1000 people per acre, you would have enough food for 36 billion people from the state of Iowa.

synaesthesisx 10y ago
A bushel of corn weighs 56 pounds (shelled) or 70 pounds (still on the ear). Using the shelled bushel in this case, 1 pound of corn = 1,656 calories so each bushel is roughly 92,000 calories. With the record yield of 500 bushels/acre that can feed 60+ people for a year! I can't think of anything else that can come close to that kind of yield. No wonder corn syrup is in everything...
- planteen 10y ago
  Whoops, forgot to multiply by 56 lbs in that
- loafa 10y ago
  I think you're making an error there somewhere, possibly mixing calorie yields per year with human requirements per day. Divide that by 365 for a more realistic estimate. About 60 people per acre if you can maintain the world record yield, or about 15 with the mean US yield.
- logfromblammo 10y ago
  500 bushels/acre is probably not scalable. For corn, if you get 150 bushels/acre, you are doing well. I think the grand champion of caloric yield per unit area is actually the sweet potato. But potato is second place, has more protein, and a better sale price. Also, sweet potato contains raffinose, meaning that it will give you gas. Browse fao.org for a bit for more information on the nutritional yields of various crops. Though last time I checked, there was no comparison with perennial tree crops like oil palm, neem, and jackfruit.
tabeth 10y ago
Really? I thought aquaponics and other advanced techniques drastically increased that by an order of magnitude. Doing a quick search, it seems that you're right. For an average person, with an average diet, to feed a SINGLE person you need an acre (with traditional farming techniques)[1]. Wow. I doubted a thousand people could realistically be fed on an acre, but I thought at least 10 would be trivial, and 100 possible with some efficient tech. Pretty eye opening, honestly (humbling moment, hah) [1] http://www.farmlandlp.com/2012/01/one-acre-feeds-a-person/ http://www.farmlandlp.com/2012/01/one-acre-feeds-a-person/ EDIT: The best I could find in terms of output in the US a farm that does about 40 tons with three acres, which is supposedly ~200 people [2] [2] https://www.splendidtable.org/story/how-to-feed-10000-people-from-food-grown-on-3-acres-in-the-city https://www.splendidtable.org/story/how-to-feed-10000-people...
- jsilence 10y ago
  Unfortunately aquaponics and vertical farming are often advertised as "the future of food" with bloated claims of yield increase. While controlled environment agriculture (CEA aka greenhouse farming) does have increased yields and an elongated production period, the gains are nowhere near the claims that are being made (factor of ten to factor of hundred). Apart from that greenhouse production is mainly used for produce and leafy greens. It does not make sense to produce grains in a greenhouse. Yet the bulk, like 90%, of our calories come from grains and leguminoses. Plant yield without artificial lighting is limited by light influx. Prof. Bugbee from NASA co-authored a paper on this titled "Exploring the Limits of Crop Productivity : I. Photosynthetic Efficiency of Wheat in High Irradiance Environments" (DOI: 10.1104/pp.88.3.869). The gist of this paper is that one gram of dry biomass needs at least in Mol of (sun)light (for lettuce, other crops need even more light per dry mass).
  - elcritch 10y ago
    It's unfortunate how much hype surrounds vertical farming and hydroponics as it'll likely cause a let down and potentially lead many people to miss the actual benefits. Vertical Ag won't completely replace large scale crop farming, especially given the record population levels we have nowadays. The "green revolution" of high yield mass crops has been a boon to world food stability. Why the hype for vertical farming then? Variety, locality, and nutrition. While bulk calories come from grains which don't grow well in vertical system, many leafy greens and vegetables do. Importantly many nutrients (especially phytochemicals) degrade very quickly after harvesting. Transporting food like strawberries or leafy greens hundreds or thousands of miles results in quite severe reduction in nutrition, and often taste suffers and require significant refrigeration to counteract. [1, 3] Great point about the lighting Influx! Indoor growing without greenhouses requires a lot of light. Alas, it's not well understood... We review a lot of lights for our customers and seem to regularly get companies who claim to increase power efficiencon over 90%! Amazing -- except they confuse lumens with light flux and won't get the corresponding plant growth. Photosynthesis requires a high light density, measured in Molson of light per volume. Kinda cool! Thanks for the link above, my coworkers will find it helpful. All that being said we ended up developing our own custom LED lights using water cooling techniques similar to Google data centers. To achieve high enough light density while not frying the plants from waste heat, we pump the heat out via a chiller system. Basically, anytime you can water cool something -- do it! ;) [2] 1: http://www.fruitandvegetable.ucdavis.edu/files/197179.pdf http://www.fruitandvegetable.ucdavis.edu/files/197179.pdf 2: https://brightagrotech.com/coolbar/ https://brightagrotech.com/coolbar/ 3: http://pure.au.dk/portal/files/45962257/PostharvestQualityChanges_afhandlingMetteMarieL_kke.pdf http://pure.au.dk/portal/files/45962257/PostharvestQualityCh... (edits: grammar and forgot a link)
Tangurena2 10y ago
I think the ballpark you are looking for would be Biosphere 2 [0]. This is a 3 acre enclosed system that supports the food and oxygen needs of 8 people, although the people lost a lot of weight and oxygen levels dropped dangerously. While this (somewhat failed) experiment is in the ballpark of what long-term spacecraft will need to sustain generations of crew, it also shows how much land is needed to supply the air we breathe. Notes: 0 - https://en.wikipedia.org/wiki/Biosphere_2 https://en.wikipedia.org/wiki/Biosphere_2

synaesthesisx 10y ago

A bushel of corn weighs 56 pounds (shelled) or 70 pounds (still on the ear). Using the shelled bushel in this case, 1 pound of corn = 1,656 calories so each bushel is roughly 92,000 calories. With the record yield of 500 bushels/acre that can feed 60+ people for a year! I can't think of anything else that can come close to that kind of yield. No wonder corn syrup is in everything...

planteen 10y ago
Whoops, forgot to multiply by 56 lbs in that
loafa 10y ago
I think you're making an error there somewhere, possibly mixing calorie yields per year with human requirements per day. Divide that by 365 for a more realistic estimate. About 60 people per acre if you can maintain the world record yield, or about 15 with the mean US yield.
logfromblammo 10y ago
500 bushels/acre is probably not scalable. For corn, if you get 150 bushels/acre, you are doing well. I think the grand champion of caloric yield per unit area is actually the sweet potato. But potato is second place, has more protein, and a better sale price. Also, sweet potato contains raffinose, meaning that it will give you gas. Browse fao.org for a bit for more information on the nutritional yields of various crops. Though last time I checked, there was no comparison with perennial tree crops like oil palm, neem, and jackfruit.

tabeth 10y ago

Really? I thought aquaponics and other advanced techniques drastically increased that by an order of magnitude. Doing a quick search, it seems that you're right. For an average person, with an average diet, to feed a SINGLE person you need an acre (with traditional farming techniques)[1]. Wow. I doubted a thousand people could realistically be fed on an acre, but I thought at least 10 would be trivial, and 100 possible with some efficient tech. Pretty eye opening, honestly (humbling moment, hah) [1] http://www.farmlandlp.com/2012/01/one-acre-feeds-a-person/ http://www.farmlandlp.com/2012/01/one-acre-feeds-a-person/ EDIT: The best I could find in terms of output in the US a farm that does about 40 tons with three acres, which is supposedly ~200 people [2] [2] https://www.splendidtable.org/story/how-to-feed-10000-people-from-food-grown-on-3-acres-in-the-city https://www.splendidtable.org/story/how-to-feed-10000-people...

jsilence 10y ago
Unfortunately aquaponics and vertical farming are often advertised as "the future of food" with bloated claims of yield increase. While controlled environment agriculture (CEA aka greenhouse farming) does have increased yields and an elongated production period, the gains are nowhere near the claims that are being made (factor of ten to factor of hundred). Apart from that greenhouse production is mainly used for produce and leafy greens. It does not make sense to produce grains in a greenhouse. Yet the bulk, like 90%, of our calories come from grains and leguminoses. Plant yield without artificial lighting is limited by light influx. Prof. Bugbee from NASA co-authored a paper on this titled "Exploring the Limits of Crop Productivity : I. Photosynthetic Efficiency of Wheat in High Irradiance Environments" (DOI: 10.1104/pp.88.3.869). The gist of this paper is that one gram of dry biomass needs at least in Mol of (sun)light (for lettuce, other crops need even more light per dry mass).
- elcritch 10y ago
  It's unfortunate how much hype surrounds vertical farming and hydroponics as it'll likely cause a let down and potentially lead many people to miss the actual benefits. Vertical Ag won't completely replace large scale crop farming, especially given the record population levels we have nowadays. The "green revolution" of high yield mass crops has been a boon to world food stability. Why the hype for vertical farming then? Variety, locality, and nutrition. While bulk calories come from grains which don't grow well in vertical system, many leafy greens and vegetables do. Importantly many nutrients (especially phytochemicals) degrade very quickly after harvesting. Transporting food like strawberries or leafy greens hundreds or thousands of miles results in quite severe reduction in nutrition, and often taste suffers and require significant refrigeration to counteract. [1, 3] Great point about the lighting Influx! Indoor growing without greenhouses requires a lot of light. Alas, it's not well understood... We review a lot of lights for our customers and seem to regularly get companies who claim to increase power efficiencon over 90%! Amazing -- except they confuse lumens with light flux and won't get the corresponding plant growth. Photosynthesis requires a high light density, measured in Molson of light per volume. Kinda cool! Thanks for the link above, my coworkers will find it helpful. All that being said we ended up developing our own custom LED lights using water cooling techniques similar to Google data centers. To achieve high enough light density while not frying the plants from waste heat, we pump the heat out via a chiller system. Basically, anytime you can water cool something -- do it! ;) [2] 1: http://www.fruitandvegetable.ucdavis.edu/files/197179.pdf http://www.fruitandvegetable.ucdavis.edu/files/197179.pdf 2: https://brightagrotech.com/coolbar/ https://brightagrotech.com/coolbar/ 3: http://pure.au.dk/portal/files/45962257/PostharvestQualityChanges_afhandlingMetteMarieL_kke.pdf http://pure.au.dk/portal/files/45962257/PostharvestQualityCh... (edits: grammar and forgot a link)

Tangurena2 10y ago

I think the ballpark you are looking for would be Biosphere 2 [0]. This is a 3 acre enclosed system that supports the food and oxygen needs of 8 people, although the people lost a lot of weight and oxygen levels dropped dangerously. While this (somewhat failed) experiment is in the ballpark of what long-term spacecraft will need to sustain generations of crew, it also shows how much land is needed to supply the air we breathe. Notes: 0 - https://en.wikipedia.org/wiki/Biosphere_2 https://en.wikipedia.org/wiki/Biosphere_2