A Hydroponics-based Agriculture System

[voidbeetles]

Hi!

One of my current writing projects is set in a civilization that has, for thousands of years, lived in a sort of large scifi underground bunker. They have easy access to water, very little access to soil (they're able to compost biomass, add minerals, etc, but that will only get you so far), and no access to sunlight (grow lights will have to suffice) - for these reasons, I imagine that their agriculture system is mostly hydroponics-based. Though I've done a little research on hydroponics, I'm having difficulty extrapolating this information to my worldbuilding, mostly because a lot of the info I've found relates to singular plants without giving a good sense of what fares better/worse compared to others. And also just because I have a hard time wrapping my head around plant cultivation in general, I think. I was wondering if anyone here had any insights! (Or suggestions of topics/resources to look into more!)

The big questions I'm thinking most about are:

• Compared to, say, the modern Western world, would certain foods/food groups be underrepresented or over-represented in this fictional world's cuisine? (for example, I imagine that rice might be the main staple, as flooding rice fields is pretty important to cultivating it... and that potatoes might not be such a good choice, as their "main thing" is growing beneath the soil?)
• What effect would this have on the plant fibers that are most commonly used for making clothes (and other fiber technology like rope)? That is: how would cotton, linen, hemp, etc fare? Would a certain one of these plants be more common? More expensive? Quicker/easier to grow/harvest on large scales? (This question is especially relevant because my protagonist has an interest in textiles.)

Comments

[armiphlage]

With respect to linen, the rule of thumb is that to grow enough for a bedsheet, you need growing area of at least that size. That space would be better spent on food crops.

Hemp, cotton, and flax might be grown primarily for their oil-rich seeds, with the fibrous stalks merely a useful byproduct.

Perhaps the society would need to restrict the use of textiles. Instead of beds, they could sleep on piles of sand, rinsing the top layer in a bucket instead of cleaning the sheets. Ambient air temperatures would need to be higher, so people would need less clothing.

[winterbird]

Perhaps the society would need to restrict the use of textiles.

For sure! Although depending on what access they have, they'll need access to textiles (or rock wool) for hydroponics to be viable, and will need a lot of dry goods for compost (though hay/straw/oven-dried plant matter could fill this gap). I assume a really good heating/combustion system would help in a lot of ways in this sense for producing ash as a growth material, breaking down otherwise hard to break-down materials, producing dry matter for composts. Flax is definitely not that viable overall, even when compared to other textile plants.

Sand is actually not that common! I remember researching this for a biome and mineral sands aren't super common and usually require certain geography and rock composition to even be present in refined abundance. There are plenty of biomes that actually do not have sand in any meaningful way, and have to export it in (it's one of my state's major global exports, even more valuable than the old growth hardwood on top that they destroy/log to get to it). Sand is an abrasive, it's not sterile, and gets into wounds very easily as a foreign body and is wonderful at causing infection, so sleeping on it would require more clothing and fabric, and not less, in many cases.

Culturally sleeping on sand has been useful for some folks in certain cultures as a form of comfort (though rarely health, except for certain conditions), but not as a pragmatic way of sleeping on a very regular basis outside of wellness community stuff. It's also hard, which can be good for some forms of disease but actually very bad for others. Finally, with sand not being sterile, being an abrasive, and absolutely *loving* to find its way into crevices, wounds, cuts, etc., rinsing it in a bucket is going to do absolutely nothing. It would need proper sterilisation on a regular basis, which might be possible again if this underground bunker has really amazing combustion/oven/heat-based systems.

(Granted our sheets are not completely sterile either, but they're less likely to find their way into wounds and crevices and then remain there until we become like, infected and/or septic).

Pure sand is rare outside of deserts. Many places that have it, have shipped it in. The best places to have it readily available for a population are along coastlines that have or used to have coral reefs in abundance (which is less great for underground bunker locations) because one of the fastest ways to get fresh sand is parrotfish + coral, without having to wait the millions of years for erosion to keep doing its job. Alternatively in places where fossilised sand dunes are present (Western Australia etc.) inland and can be mined from deep under the earth (possibly even where the bunker is placed, though again, probably not super stable for an underground bunker to be).

I mean it's also totally possible that the society uses sand and just deals with all the infection / increased rate of certain diseases / abrasion wounds / increased likelihood of bedsores in those who have limited movement or have to lie down to rest a lot, you can go really dystopian with sand, tbh (and also with diseases in hydroponics labs).

It's also going to rule out a lot of sleeping positions. Research has indicated that any position that allows the penis to touch soil/sand leads to really fun things like sand in the urethra and foreskin, and if there are insects etc. insect bites. (Similar in buttcracks). This society is going to want to be fully able-bodied to support the viable sleeping positions on sand, which they're not really likely to be in a dystopia spending 1000s of years underground and genetically bottlenecking themselves over time.

* There are cultures that do sleep on sand, like the residents of Sumenep, but that is almost entirely down to the composition of the crystal sand, which is non-sticky, shipped/carted in, and cannot be replaced by local sand. But when a story is fiction, you can always just hand wave and say that these sands are just there in abundance and then you'll have less issues with the sand migrating / causing abrasion issues. But most of the sand in the world is not the sand used in Sumenep. In places in Indonesia where the elderly use sleeping sand, it's sand entirely dependent on parrotfish/reef systems (i.e. white coral reef sand), which is less likely to be present in a dystopia. All sands are definitely not made equal, though...depending on how advanced the underground society is, they could make/refine it themselves.

There's definitely ways to do it! But not in a 'regular sand can be slept on safely' kind of way sdalkfja