But why would farmers change from field to partial field strawberries without a clear upsite?
They wont.
The major downside to those vertical farming systems is the specialty product cost (Like the fiber/plastic little containers). That and you would have to spend time and money re configuring from your original setup.
Also it has issues with irrigation, those usually use aeriation systems (think bubblers) that need to be cleaned frequently, hard water will gunk them up. Another one is mold/algae control in those.
For example, some of the vert systems rely on water constantly flowing down a vertical pipe at a trickle. Algae, sludge, hard water issues galore. Cheaper and easier to flood a row or use sprinklers since the sprikler line nominally is self enclosed instead of open to the environment.
Edit: High tunnel (greenhouse but plastic film instead of proper pannels) + water "gutter" is a proper cultivation method.
Urban gardens dont work, but you can still produce alot of food in an urban environment.
Pollution being absorbed is a concern. Heavy metal absorption particularly.
our local parks are full nut trees and everybody is allowed to pick them up.
Legal issues, some retard gets sick and sues.
chestnuts and walnuts trees are beautyful and they hproduce alot of nuts
Try planting a walnut on the top of a roof and I will laugh when that tree decides to either
1) Have the taproot circle and rootbound the tree, stunting, and dying.
2)Have the taproot rack your roof (yes, it can be
that strong)
3) Collapse and fall down, injuring you or others and damaging the house (Hint: Fungal rots)
The root zone of the tree is roughly 2-3x it's canopy. Think about that for a second.
Now for commercial production it becomes even less viable. You've got to keep water running in some configuration throughout the critical root zone (1-1.5x the canopy), while maximizing sunlight into the canopy, while keeping debris from landing into said water, while also being able to maneuver around equipment (airblast sprayers, ladders, pruners, etc). Did I also mention you can't just dump a vat of X mineral needed into the water or it will shock and kill the tree?
Finally, walnut trees grow slow as molasses, unless you grow a Thompson black walnut maybe (And black walnut isn't easy to crack and hence not "sellable" because first world issues). Chestnuts are a meme food because lol Chestnut blight for American Chestnuts and lol a "small" (In US terms) drought will nuke your Chinese chestnuts.