4 ms·

Probably one of the most boring and most important problems in the world. Not enough is being done to address these issues, mostly because it would threaten hu

Probably one of the most boring and most important problems in the world. Not enough is being done to address these issues, mostly because it would threaten huge commercial farms. I suspect that the number of farmers is going to grow very substantially in the next 20-50 years as people recognize that you can't steward 1000 acres all by yourself. The practical limit of how many people an acre of land can support is driven almost entirely by how many people are working it. There's the upper limit on inbound sunlight of course, but that's a pretty high limit relative to what industrial agribusiness is doing these days.

hollerith 12y ago
I don't understand your comment. >The practical limit of how many people an acre of land can support is driven almost entirely by how many people are working it. Does that not imply that loss of soil will not result in starvation, just the need for more farmers? Do you agree or disagree with, "Destroy the soil and we all starve"?
- green7ea 12y ago
  From what I understood, he implied that the more people work a piece of land, the more fertile they can make it.
- msandford 12y ago
  I totally agree with the statement. If you can have 2x as many people work on a piece of land and get 2x the production from it (relative to industrial agribusiness) that's very interesting. That means that the limit for how much food we can get is due to the number of farmers, not the amount of acres. And the idea that we could ruin 20-30% of the farmland in the world and still recover is very encouraging, because you can make up for that kind of loss by simply increasing the number of farmers and production would go up more than enough to make up for it. Also even once land is "ruined" it's still not ruined forever. It just takes some years of rest and rehabilitation before it is fertile again. You can grow peanuts to fix nitrogen. You can plant grass and graze cattle on it for several years to fix large amounts of biomass into the land and kickstart the process of renewal. Medieval farmers knew about this and they had a "two field" system where they farmed one field and left the other fallow. Eventually they figured out that 50% rest wasn't strictly necessary and went to the three field system where a field got 33% rest. Right now most farmland gets 0% rest which is part of the problem. Lets suppose that there are diminishing returns to adding farmers. Eventually you run into the limits of sunlight of course. But if most farmland is only 10% efficient and lets say that quadrupling the number of farmers per acre only triples production. By teaching people to be farmers and to manage their land very jealously we could have well over half the fields in recovery all the time and still have enough food.
  - joshuapants 12y ago
    > That means that the limit for how much food we can get is due to the number of farmers, not the amount of acres I think a pretty serious limit would be that most plants need space, you can only fit a limited number of a crop in an acre and after a certain (fairly low) point having more farmers would not help anything.
    - msandford 12y ago
      Agreed, but industrial agribusiness is predicated on huge automation and the idea that one farmer can farm hundred or thousands of acres. That's an efficient use of labor, but not of acres. We might be getting to the point that land is more valuable than labor and thus it makes sense to spend more human effort per acre than in the past. Here are people in LA that grow a huge amount of food in their backyard, 1/10 of an acre: https://www.youtube.com/watch?v=NCmTJkZy0rM https://www.youtube.com/watch?v=NCmTJkZy0rM Here's a guy in Canada that makes a legit living urban farming 1/3 of an acre: https://www.youtube.com/watch?v=TnCIlq0KPw0 https://www.youtube.com/watch?v=TnCIlq0KPw0 There are tons of additional examples on youtube of other people doing very similar things. The point, though, is that it's very intensive on a labor per acre basis. You can't do this kind of farming with big tractors over thousands of acres with just a few people, you need several people per acre for it to work. But it does work! Yes there is a limit eventually, but the point isn't as low as you think.
      - joshuapants 12y ago
        The LA example is interesting, I'd be interested in seeing a more detailed breakdown of what exactly they grew because pounds of food aren't exactly fungible (a pound of lettuce has 77 calories, a pound of potatoes has ~350). From some back of the napkin math, it seems that current farming techniques yield about 50,000 pounds of potatoes per acre, so on the 1/10 acre scale in terms of vegetable matter they outpace the LA farm (though this will vary by crop. It might make more sense to compare calories per acre). I think you have a point, it's certainly worth looking into whether the gains from more labor-intensive farming are greater than the cost of labor when adopted en masse.

hollerith 12y ago

I don't understand your comment. >The practical limit of how many people an acre of land can support is driven almost entirely by how many people are working it. Does that not imply that loss of soil will not result in starvation, just the need for more farmers? Do you agree or disagree with, "Destroy the soil and we all starve"?

green7ea 12y ago
From what I understood, he implied that the more people work a piece of land, the more fertile they can make it.
msandford 12y ago
I totally agree with the statement. If you can have 2x as many people work on a piece of land and get 2x the production from it (relative to industrial agribusiness) that's very interesting. That means that the limit for how much food we can get is due to the number of farmers, not the amount of acres. And the idea that we could ruin 20-30% of the farmland in the world and still recover is very encouraging, because you can make up for that kind of loss by simply increasing the number of farmers and production would go up more than enough to make up for it. Also even once land is "ruined" it's still not ruined forever. It just takes some years of rest and rehabilitation before it is fertile again. You can grow peanuts to fix nitrogen. You can plant grass and graze cattle on it for several years to fix large amounts of biomass into the land and kickstart the process of renewal. Medieval farmers knew about this and they had a "two field" system where they farmed one field and left the other fallow. Eventually they figured out that 50% rest wasn't strictly necessary and went to the three field system where a field got 33% rest. Right now most farmland gets 0% rest which is part of the problem. Lets suppose that there are diminishing returns to adding farmers. Eventually you run into the limits of sunlight of course. But if most farmland is only 10% efficient and lets say that quadrupling the number of farmers per acre only triples production. By teaching people to be farmers and to manage their land very jealously we could have well over half the fields in recovery all the time and still have enough food.
- joshuapants 12y ago
  > That means that the limit for how much food we can get is due to the number of farmers, not the amount of acres I think a pretty serious limit would be that most plants need space, you can only fit a limited number of a crop in an acre and after a certain (fairly low) point having more farmers would not help anything.
  - msandford 12y ago
    Agreed, but industrial agribusiness is predicated on huge automation and the idea that one farmer can farm hundred or thousands of acres. That's an efficient use of labor, but not of acres. We might be getting to the point that land is more valuable than labor and thus it makes sense to spend more human effort per acre than in the past. Here are people in LA that grow a huge amount of food in their backyard, 1/10 of an acre: https://www.youtube.com/watch?v=NCmTJkZy0rM https://www.youtube.com/watch?v=NCmTJkZy0rM Here's a guy in Canada that makes a legit living urban farming 1/3 of an acre: https://www.youtube.com/watch?v=TnCIlq0KPw0 https://www.youtube.com/watch?v=TnCIlq0KPw0 There are tons of additional examples on youtube of other people doing very similar things. The point, though, is that it's very intensive on a labor per acre basis. You can't do this kind of farming with big tractors over thousands of acres with just a few people, you need several people per acre for it to work. But it does work! Yes there is a limit eventually, but the point isn't as low as you think.
    - joshuapants 12y ago
      The LA example is interesting, I'd be interested in seeing a more detailed breakdown of what exactly they grew because pounds of food aren't exactly fungible (a pound of lettuce has 77 calories, a pound of potatoes has ~350). From some back of the napkin math, it seems that current farming techniques yield about 50,000 pounds of potatoes per acre, so on the 1/10 acre scale in terms of vegetable matter they outpace the LA farm (though this will vary by crop. It might make more sense to compare calories per acre). I think you have a point, it's certainly worth looking into whether the gains from more labor-intensive farming are greater than the cost of labor when adopted en masse.