With aquaponics, you farm fish, and process the fish poop to be used as the sole fertilizer for growing food hydroponically. 20 foot urban farm has free plans for how to do this with a shipping container as the basic structure with a hydroponic greenhouse on top. This can be done in small spaces in cities.
Politics in the Zeros
"A republic, if you can keep it." Defeat MAGA
Politics in the Zeros
"A republic, if you can keep it." Defeat MAGA