Citation? I can't imagine they would use little or none unless they were farming something specific, like rice, which can grow under water or if it's grown indoors.
> What is the most sustainable and ecologically friendly way to get food then? Local farms, farmers markets, or growing your own food seems like the best but I don't think that's sustainable for the whole population.
So I'm having trouble finding the study I read a few years back but it essentially found that large, centralized farms are the most efficient because our transportation has gotten so good and many plants grow better in specific climates versus growing everything locally. So if you have enough scale then centralized, huge farms seems to be the way to go.
However that's using today's farming. I've seen many write-ups calling for entire buildings with hundreds of floors for farming. If we can get those energy efficient then we should be able to create the perfect climate for each plant and we'll be taking up vertical space so it'll be better land usage too.
Though that would suck if power died from, say, a solar flare and all of our food was in these towers...heh