This is all @lilFluff‘s fault. Brought on by a toot thread in a now-deleted server, quoted below. Science! ‘verse.
“I think we’ve got it!”
Liam stopped at the door and peered at his scientists. They had to be his; they were in his building.
But he couldn’t remember what this room – tucked behind the break room and next to the fire escape – was even for.
The scientist looking at him looked like she’d forgotten what a brush was for, but she also looked thrilled.
“Tell me more.”
“The square meter challenge. It was a problem for interns, twenty years ago.”
Liam made a mental note to make sure someone in HR knew about this department.
“So, considering you cannot grow anything in a square meter; food has three dimensions, we decided to work with a cubic meter. We did some decent work by putting a fish base underneath and cycling the water through a hydro system. We added on some mice, but we were still getting only enough calories per year for about one person for one-third of a year. We upped the caloric output of the food we were growing, aided by the fertilizer and working on some bedrock work by the bio-engineering department, ditto for the fish and mice – nothing larger than mice could pasture on the space we had, even double-stacking the growing space. But we could not get it to sufficient calories in the time allotted.”
The scientist grinned. “That’s when we realized that we could use prior time. Now, until we run out of past years, we’re growing in four dimensions and we can feed a family of four to ten just fine in one cubic meter of space.”
“Plus lights,” her assistant added cheerfully. “No sunlight down here.”
Liam cleared his throat. “Very – very good. Very good indeed.” He needed to talk to HR immediately.
“Would you like a sample of our bean crop? Quite tasty, especially in a mouse-bean stew with fried tilapia…”
Toots quoted with permission, because they’re follower-locked:
Lilfluff: now I want to track down the anime review that mentioned among other things that the writer of the original manga insisted that, “No, really, you can easily feed a family of four for a whole year with a planter that fits on a balcony and no chemical fertilizers.” (Don’t recall the title, but it was apparently more or less essentially, “Luddite magical girl saves world from technology.”)
I tried searching the site I thought had the review but no luck so far. The mangaka was apparently quite convinced of this. That something on the order of one square meter of unpolluted soil + water was all that was needed to feed a person for a year. Any trouble actually doing it was all the fault of pollution and disinformation from Big Ag.
Somehow I don’t think that’s working without magical girl intervention.