A revolution in farming

On a recent walk one afternoon in Manhattan, I stumbled upon a shipping container. Parked on a small patch of concrete next to a subway exit in Soho, the steel box took up about the same amount of space as several parked cars. It was noticeable for its novelty but otherwise unobtrusive. I peered inside and saw electric pink lights and column after column of leafy greens. The shipping container, it turns out, contained a hydroponic farming system capable of producing between two to four...