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I’ve always been super pumped about hydroponics and the absurd yields you can get from it. Hopefully it gets cheaper and cheaper over time.

fatherzine 4y ago
Hydroponics sounds great on paper. Until you see the sludge they feed the plants with. Given the incentive to cut costs, especially where it's hard to see and/or measure, not sure I want to get anywhere close to the resulting produce.
- FredPret 4y ago
  https://daily.jstor.org/a-history-of-human-waste-as-fertilizer/ https://daily.jstor.org/a-history-of-human-waste-as-fertiliz...
- LordDragonfang 4y ago
  This objection baffles me. Traditional agriculture has used literal feces to "feed" plants since its inception, and frequently uses bones and blood as nutrient input. I'm eating the resulting food, not the rot and excrement used to feed it.
  - fatherzine 4y ago
    That is a fault of imagination ;) Think "processed oil refinery sludge" or some other such industrial horror. Oh, sure, there is a shit ton of heavy metals and/or who knows what other garbage in there, but it's below the FDA limit (hello VW wink wink), so let's roll with it straight to mass human consumption.
- lathyrus_long 4y ago
  What do you mean by "sludge"? Typical hydroponic solution just looks like water, thus the name. The fertilizers used are higher purity ("greenhouse grade", "ultra-soluble", etc.) than those applied to soil, since impurities risk clogging the fertigation equipment.
watwut 4y ago
It is cheap way to get badly tasting vegetables. There is real, huge noticeable difference between tomatoes raised via hydroponics and not. Unless they manage to make them super packed with nutrients, which they are definitely not, there is zero reason to eat them.
jahnu 4y ago
Solar Foods and similar are also promising ways to massively reduce land use https://en.m.wikipedia.org/wiki/Solar_Foods https://en.m.wikipedia.org/wiki/Solar_Foods
bshipp 4y ago
I work in hydroponics and when I describe it to someone new I mention it's like creating 15 acres of agricultural land out of thin air. Of course that depends on the crop, but there can be huge advantages to covered agriculture.
- actionfromafar 4y ago
  Is it still mostly salads or is there hope for high-calorie hydroponics?
  - hanniabu 4y ago
    All depends on the cost of the land it's on, electricity/water costs, the growing apparatus, whether it requires artificial light, and what the market rates for the crop are. So yeah, there's a lot of variables as one could imagine.
  - colechristensen 4y ago
    It's still mostly salads.
- Gordonjcp 4y ago
  > I mention it's like creating 15 acres of agricultural land out of thin air. So you can just grow things hydroponically out of nothing? You don't need masses of petrochemical-derived fertilisers and plastics?
  - bombcar 4y ago
    Hydroponics are starting to sound like perpetual motion machines, where you can get more calories out than you put in. It kinda works for farmland because it’s basically solar panels as plants.
    - Gordonjcp 4y ago
      I know, right? And if you've got farmland you can't easily put plants on you can put animals on that instead, and eat the animals and use the stuff the animals leave behind to grow plants. It's almost like an ecosystem that has worked for hundreds of thousands of years is actually a pretty solid idea.
legulere 4y ago
Hydroponics only makes sense for high price crops like salad or vegetables which make up only small amounts of agriculture. It’s way too expensive for the crops that provide most of the calories consumed by humans or animal feed: wheat, maize, soy
- hanniabu 4y ago
  > Hydroponics only makes sense for high price crops like salad or vegetables That's only true if it's in the city or other location with high cost/sqft land
- tekno45 4y ago
  imagine if we can reclaim all the land that salad and veggies use and replace it with good grains? solutions aren't always mutually exclusive.
  - yuliyp 4y ago
    ... that'll be a drop in the bucket. cereal grains alone use more than 10x [1] the amount of land used for vegetables. Add in other large users (coarse grain / oil crops) and it's over 20x, meaning you'd get like a 5% increase by replacing all vegetable land with grains. [1] https://ourworldindata.org/land-use#land-use-by-crop https://ourworldindata.org/land-use#land-use-by-crop
    - tekno45 4y ago
      thanks for sharing, thats pretty good data. can't disagree with that. seems like even more reason to not use the land for things that can be grown vertically/hydroponically. But definitely something i'll be reading more on, thanks for the resource.
  - Gordonjcp 4y ago
    It wouldn't be particularly nutritionally useful, and you'd be able to grow grain for a couple of years before your soil turned into dust. That's why America starved in the 1930s.
fredrikholm 4y ago
Hydroponics are limited to low-calorie foods such as lettuce, herbs, spinach etc due to constraints in the method itself. High calorie and/or high fiber foods require complex rhizospheres which is currently only found in healthy soil. To add injury, the substrate used to provide nutrients to hydroponic plants either require petrochemicals or other plant material (compost, husks, seeds...) to mimic a complete nutrient profile. Perhaps there are solvable problems, but given the already high costs and limitations, hydro is not an option if our ecosystems collapse.
- lathyrus_long 4y ago
  > High calorie and/or high fiber foods require complex rhizospheres which is currently only found in healthy soil. What is your source for this claim? Major grains (wheat, corn, rice, etc.) grow fine hydroponically--I've actually seen modern conventional agriculture described derisively as a hydroponic system using the sterilized natural soil as its inert medium. That description seems basically correct to me, though I don't think it's necessarily bad. Production of grains in systems analogous to hydroponic vegetable production would certainly be possible, just currently uneconomic: https://www.pnas.org/doi/10.1073/pnas.2002655117 https://www.pnas.org/doi/10.1073/pnas.2002655117 The major benefit of hydroponics is in achieving very high yield per acre. This is important e.g. when growing perishable vegetables in expensive greenhouses near densely-populated areas. For grains that are readily dried, stored, and shipped, it's currently far cheaper to cultivate more acres in remote areas at lower yield per acre. The "petrochemical" claim is also confusing. The point of hydroponics is that the plant gets nutrients from the solution, not from the inert substrate. Typical hydroponic substrates may be plant-based (e.g. coir) or not (e.g. rockwool), but in neither case are they providing significant fertility, nor making significant use of petrochemicals. Obviously their energy inputs for production and transportation often come from petroleum; but that's true for almost any human activity today, including organic agriculture. A few niche applications do use petrochemical-based substrates (e.g. phenolic foam), but very rarely. The synthetic nitrogen fertilizers dissolved in the nutrient solution often use hydrogen from natural gas, since that's the cheapest source, but could use any other source of hydrogen (e.g., electrolysis of water) instead. Here's an article studying those economics: https://www.frontiersin.org/articles/10.3389/fenrg.2021.580808/full https://www.frontiersin.org/articles/10.3389/fenrg.2021.5808...

fatherzine 4y ago

Hydroponics sounds great on paper. Until you see the sludge they feed the plants with. Given the incentive to cut costs, especially where it's hard to see and/or measure, not sure I want to get anywhere close to the resulting produce.

FredPret 4y ago
https://daily.jstor.org/a-history-of-human-waste-as-fertilizer/ https://daily.jstor.org/a-history-of-human-waste-as-fertiliz...
LordDragonfang 4y ago
This objection baffles me. Traditional agriculture has used literal feces to "feed" plants since its inception, and frequently uses bones and blood as nutrient input. I'm eating the resulting food, not the rot and excrement used to feed it.
- fatherzine 4y ago
  That is a fault of imagination ;) Think "processed oil refinery sludge" or some other such industrial horror. Oh, sure, there is a shit ton of heavy metals and/or who knows what other garbage in there, but it's below the FDA limit (hello VW wink wink), so let's roll with it straight to mass human consumption.
lathyrus_long 4y ago
What do you mean by "sludge"? Typical hydroponic solution just looks like water, thus the name. The fertilizers used are higher purity ("greenhouse grade", "ultra-soluble", etc.) than those applied to soil, since impurities risk clogging the fertigation equipment.

watwut 4y ago

It is cheap way to get badly tasting vegetables. There is real, huge noticeable difference between tomatoes raised via hydroponics and not. Unless they manage to make them super packed with nutrients, which they are definitely not, there is zero reason to eat them.

jahnu 4y ago

Solar Foods and similar are also promising ways to massively reduce land use https://en.m.wikipedia.org/wiki/Solar_Foods https://en.m.wikipedia.org/wiki/Solar_Foods

bshipp 4y ago

I work in hydroponics and when I describe it to someone new I mention it's like creating 15 acres of agricultural land out of thin air. Of course that depends on the crop, but there can be huge advantages to covered agriculture.

actionfromafar 4y ago
Is it still mostly salads or is there hope for high-calorie hydroponics?
- hanniabu 4y ago
  All depends on the cost of the land it's on, electricity/water costs, the growing apparatus, whether it requires artificial light, and what the market rates for the crop are. So yeah, there's a lot of variables as one could imagine.
- colechristensen 4y ago
  It's still mostly salads.
Gordonjcp 4y ago
> I mention it's like creating 15 acres of agricultural land out of thin air. So you can just grow things hydroponically out of nothing? You don't need masses of petrochemical-derived fertilisers and plastics?
- bombcar 4y ago
  Hydroponics are starting to sound like perpetual motion machines, where you can get more calories out than you put in. It kinda works for farmland because it’s basically solar panels as plants.
  - Gordonjcp 4y ago
    I know, right? And if you've got farmland you can't easily put plants on you can put animals on that instead, and eat the animals and use the stuff the animals leave behind to grow plants. It's almost like an ecosystem that has worked for hundreds of thousands of years is actually a pretty solid idea.

legulere 4y ago

Hydroponics only makes sense for high price crops like salad or vegetables which make up only small amounts of agriculture. It’s way too expensive for the crops that provide most of the calories consumed by humans or animal feed: wheat, maize, soy

hanniabu 4y ago
> Hydroponics only makes sense for high price crops like salad or vegetables That's only true if it's in the city or other location with high cost/sqft land
tekno45 4y ago
imagine if we can reclaim all the land that salad and veggies use and replace it with good grains? solutions aren't always mutually exclusive.
- yuliyp 4y ago
  ... that'll be a drop in the bucket. cereal grains alone use more than 10x [1] the amount of land used for vegetables. Add in other large users (coarse grain / oil crops) and it's over 20x, meaning you'd get like a 5% increase by replacing all vegetable land with grains. [1] https://ourworldindata.org/land-use#land-use-by-crop https://ourworldindata.org/land-use#land-use-by-crop
  - tekno45 4y ago
    thanks for sharing, thats pretty good data. can't disagree with that. seems like even more reason to not use the land for things that can be grown vertically/hydroponically. But definitely something i'll be reading more on, thanks for the resource.
- Gordonjcp 4y ago
  It wouldn't be particularly nutritionally useful, and you'd be able to grow grain for a couple of years before your soil turned into dust. That's why America starved in the 1930s.

fredrikholm 4y ago

Hydroponics are limited to low-calorie foods such as lettuce, herbs, spinach etc due to constraints in the method itself. High calorie and/or high fiber foods require complex rhizospheres which is currently only found in healthy soil. To add injury, the substrate used to provide nutrients to hydroponic plants either require petrochemicals or other plant material (compost, husks, seeds...) to mimic a complete nutrient profile. Perhaps there are solvable problems, but given the already high costs and limitations, hydro is not an option if our ecosystems collapse.

lathyrus_long 4y ago
> High calorie and/or high fiber foods require complex rhizospheres which is currently only found in healthy soil. What is your source for this claim? Major grains (wheat, corn, rice, etc.) grow fine hydroponically--I've actually seen modern conventional agriculture described derisively as a hydroponic system using the sterilized natural soil as its inert medium. That description seems basically correct to me, though I don't think it's necessarily bad. Production of grains in systems analogous to hydroponic vegetable production would certainly be possible, just currently uneconomic: https://www.pnas.org/doi/10.1073/pnas.2002655117 https://www.pnas.org/doi/10.1073/pnas.2002655117 The major benefit of hydroponics is in achieving very high yield per acre. This is important e.g. when growing perishable vegetables in expensive greenhouses near densely-populated areas. For grains that are readily dried, stored, and shipped, it's currently far cheaper to cultivate more acres in remote areas at lower yield per acre. The "petrochemical" claim is also confusing. The point of hydroponics is that the plant gets nutrients from the solution, not from the inert substrate. Typical hydroponic substrates may be plant-based (e.g. coir) or not (e.g. rockwool), but in neither case are they providing significant fertility, nor making significant use of petrochemicals. Obviously their energy inputs for production and transportation often come from petroleum; but that's true for almost any human activity today, including organic agriculture. A few niche applications do use petrochemical-based substrates (e.g. phenolic foam), but very rarely. The synthetic nitrogen fertilizers dissolved in the nutrient solution often use hydrogen from natural gas, since that's the cheapest source, but could use any other source of hydrogen (e.g., electrolysis of water) instead. Here's an article studying those economics: https://www.frontiersin.org/articles/10.3389/fenrg.2021.580808/full https://www.frontiersin.org/articles/10.3389/fenrg.2021.5808...