3 ms·

I do some work on crop modeling. A few years ago at a project meeting, in the evening in a bar, we did some rough calculations; there were agricultural engineer

by roel_v 10y ago

I do some work on crop modeling. A few years ago at a project meeting, in the evening in a bar, we did some rough calculations; there were agricultural engineers and agricultural economists in our group, so it wasn't completely amateur hour (but not scientifically robust either, of course). Anyway, the result was that in Western Europe you need about 100m2 per person to grow enough food to sustain oneself for a year. This took into account that you need to grow crops that keep a long time to last you through winter etc. It didn't particularly consider variety in crops (neither for taste not for soil management purposes), but it wasn't potatoes year round either. You need to be a competent farmer as well, but it didn't consider really high tech closed-greenhouse-like setups either. Still, that was a sobering number for many in the crowd - it completely undermines the whole 'self-sufficiency = sustainable' mantra.

justin_vanw 10y ago
100m^2 doesn't seem like so much to me at all, certainly not sobering. This would mean one acre of land would sustain about 40 people (or 100 per hectare). Taking wikipedia's number of 13,958,000 km^2 of arable land in the world, this would mean a maximum world population of 137,963,876,580, which is about 20x the current world population. Of course, this assumes equal quality of land to the land in your rough calculations, and I am guessing your number is assuming far more intensive cultivation than is typical (typical numbers I've seen are 1-2 acres / person).
- TheSpiceIsLife 10y ago
  The full calculation would also need to take in to consideration wastage / spoilage; crop failure; loss to pests; nutrient density (probably can't thrive off potatoes and corn only); animal feed (pets as well as animals for food). Having said that, I'll now go on to say: with one inhabited planet there are limits to resources, but the limits to human resourcefulness are undefined.
  - rahkiin 10y ago
    Don't eat animals. One problem solved. Might want to have some cows for milk and using their waste as fertilizer Edit: the not eating animals is not in a vegatarian way. I love meat. But if you want to fully sustain yourself on the smallest area possible, animals do not aid your cause.
    - nitrogen 10y ago
      Hens could probably be useful, as they can turn pests into eggs.
riffraff 10y ago
Are you sure you didn't mean 100 by 100 I.e. 10k m2? 100 m2 is practically nothing.
mattgrice 10y ago
Did you drop a zero? On an all-potato diet, assuming intensive cultivation (40,000 lbs/acre yield) you could feed about 20 people on one acre. That's 200m^2 per person. For a varied diet that might contain chicken and eggs, 1000m^2 (a quarter acre) is more reasonable.
- mabbo 10y ago
  It's possible. I dumped a lot of variables into Wolfram Alpha in a big equation and it came out with an answer in "m^2 per person" units. Also, it's not a practical minimum but a theoretical one, like supposing we had so many plants absorbing light that it's dark underneath them, etc. In reality, potatoes can do about 17m cals per acre per year, and a human needs nearly 1m per year. In short, Matt Damon definitely wasn't growing enough potatoes (in the film version at least).

by roel_v 10y ago

justin_vanw 10y ago

100m^2 doesn't seem like so much to me at all, certainly not sobering. This would mean one acre of land would sustain about 40 people (or 100 per hectare). Taking wikipedia's number of 13,958,000 km^2 of arable land in the world, this would mean a maximum world population of 137,963,876,580, which is about 20x the current world population. Of course, this assumes equal quality of land to the land in your rough calculations, and I am guessing your number is assuming far more intensive cultivation than is typical (typical numbers I've seen are 1-2 acres / person).

TheSpiceIsLife 10y ago
The full calculation would also need to take in to consideration wastage / spoilage; crop failure; loss to pests; nutrient density (probably can't thrive off potatoes and corn only); animal feed (pets as well as animals for food). Having said that, I'll now go on to say: with one inhabited planet there are limits to resources, but the limits to human resourcefulness are undefined.
- rahkiin 10y ago
  Don't eat animals. One problem solved. Might want to have some cows for milk and using their waste as fertilizer Edit: the not eating animals is not in a vegatarian way. I love meat. But if you want to fully sustain yourself on the smallest area possible, animals do not aid your cause.
  - nitrogen 10y ago
    Hens could probably be useful, as they can turn pests into eggs.

riffraff 10y ago

Are you sure you didn't mean 100 by 100 I.e. 10k m2? 100 m2 is practically nothing.

mattgrice 10y ago

Did you drop a zero? On an all-potato diet, assuming intensive cultivation (40,000 lbs/acre yield) you could feed about 20 people on one acre. That's 200m^2 per person. For a varied diet that might contain chicken and eggs, 1000m^2 (a quarter acre) is more reasonable.

mabbo 10y ago
It's possible. I dumped a lot of variables into Wolfram Alpha in a big equation and it came out with an answer in "m^2 per person" units. Also, it's not a practical minimum but a theoretical one, like supposing we had so many plants absorbing light that it's dark underneath them, etc. In reality, potatoes can do about 17m cals per acre per year, and a human needs nearly 1m per year. In short, Matt Damon definitely wasn't growing enough potatoes (in the film version at least).