In my last Green State column, I wrote about Agriculture 2.0. The conference, held in Silicon Valley recently, brought together venture capitalists and sustainable ag startups in an effort to jump start a market for the regional distribution of fresh food.

This week I take a closer look at some of the companies that tried to catch the ear and checkbooks of the high-profile investors who packed that confab at the Four Seasons in Palo Alto.

One of the more intriguing ideas came from startups thinking outside the agribusiness box by developing urban farms in a box. Literally.

Take AeroFarms. The New York company builds aeroponic farms that fit inside containers — soil and sun not required. The containers, which can be stacked on top of each other in warehouses and old buildings, have the potential to transform blocks of abandoned structures in places like Detroit or Newark into agri-lofts tended by urban farmers.

“This puts buildings back into play with a technology that would do something productive and employ people,” Ed Harwood, AeroFarms’ founder and chief executive, told prospective investors at the conference.

Here’s how it works: Leafy greens — say, arugula or lettuce — are planted in a cloth bed and irrigated with a nutrient-infused mist that is applied directly to the plants. Light is provided by LED lamps, which are more energy efficient than conventional lighting and can be placed closer to the beds. The LED lamps also provide pest control, says Harwood, because they can be set to emit certain wavelengths that disrupt insects’ breeding.