Living under the ground with an above ground mechanical farm or just living under farmed land.
The other day I wondered if it would be possible to buy an acre of land off of a farmer and put my house under his farm land. It might require a personal waste scrubbing system but any waste could then be used to irrigate and fertilize the land. Today I expanded on the idea into buying any piece of land and then using some mechanical planter/harvester. That enables you to use any of the farmed land for food for the family.