Scientific American: The soil in Knolkhol village in southwest Bangladesh has become increasingly salty because of incursions of seawater. The situation became particularly acute in the aftermath of Cyclone Aila in 2009, which brought storm surges that broke embankments and flooded farmland. After 2009 vegetable crops planted in the ground there yielded only meager returns--if they didn't fail completely.
But for the past three years hundreds of villagers have enjoyed the bounty of so-called vertical gardens--essentially...