[simopaa]

I think that the most important potential with vertical farming is not the smaller area requirement, but the tremendous water saving that can be achieved.

For example in areas like the Middle-East, agricultural irrigation takes a huge and increasing toll on the water resources [1]. This along with the large rivers of the world (where the irrigation water usually comes from) being constantly more polluted may well increase tensions in these arid regions.

If by vertical farming techniques the need for water can be reduced as dramatically as the article states ("Aeroponic farming uses about seventy per cent less water than hydroponic farming, which grows plants in water; hydroponic farming uses seventy per cent less water than regular farming"), this by itself seems like a worthy effort for certain regions on the planet.

[1] http://www.fao.org/docrep/003/Y1860E/y1860e05.htm

[thinkcontext]

The water issue is independent of whether the farm is vertical or not. There are plenty of hydroponic farms that are in a traditional horizontal orientation, I presume aeroponics can be setup this way as well. So, I do think the smaller area is the main advantage, though I'm not convinced it is a compelling enough reason given the increased energy, land and capital costs.

I agree that water should be treated as more valuable and scarce than it currently is. You mentioned the Middle East, I saw this concept for a "seawater greenhouse" recently in Qatar and was intrigued

http://www.sciencemag.org/news/2013/11/desert-farming-experi...

In the US, I'm curious about the scalability of these water saving technologies. Could they replace a significant percentage of vegetable production of drought stricken California? As I understand it now, hydroponics is used primarily for winter production, even that competes with Colorado River dependent Arizona.

[simopaa]

You are absolutely correct about that the water aspect is not vertical related in any way. I'm just used to seeing vertical and aeroponics going so hand-in-hand that I totally forgot about the possibility to have horizontal aeroponic greenhouses.

I'm very curious as well about all of these water reducing efforts, since that may well be the largest thing that threatens the food supply in the coming decades.

[marcosdumay]

It's probably still cheaper energy-wise to clean those polluted rivers first.

I agree at some point we must start thinking about reusing agriculture water¹. But doing that when there's a perfectly good river nearby that you don't want to use just because it's polluted seems premature.

1 - Does it imply in vertical? And what would be the impact of not throwing that water at the atmosphere anymore?

[gjem97]

Right, but then we're really talking about aeroponic farming, not vertical farming.

[SamBam]

But the vast majority of vertical farms are aeroponic farms, are they not?

It's way more efficient to do aeroponic if you are vertical farming, and it's way more efficient to do vertical if you are aeroponic farming. The two work together.