Where will we grow our food in the future? And is soil optional?
Finally, one speaker that inspired delegates to think outside the box (or the farm) was Caleb Harper, founder of the CityFARM research group within the City Science Initiative at the MIT Media Lab.
A multi-disciplinary group of engineers, architects, urban planners, economists and plant scientists researching urban agricultural systems, the CityFARM team is looking at hydroponics (growing plants using mineral nutrient solutions, in water, without soil); aquaponics (combining aquaculture and hydroponics); and aeroponics (growing plants in air or mist without soil).
Kent Larson, who directs the Changing Places research group at the MIT Media Lab, told delegates: "In soil you can grow about three heads of broccoli per square foot per year. We think with aeroponics we can get up to about 18 heads in the same area.
"The question is can we actually make this work in a cost-effective way [on a larger scale] ... and it seems to point to the possibility that we can grow these high value value vegetables with 90% less water and 60% less fertilizer, so it's pretty promising."
To watch all the sessions on demand, visit the reThinkFood website.