The Future of Farming: The challenge of growing twice as much food by 2050 to feed nine billion people—with less and less land—is everyone’s problem. But scientists are hard at work fomenting a second green revolution. By Hilary Rosner Posted 08.07.2009 at 11:45 am Desert Oasis The Sahara Forest Project will use concentrating solar power to provide energy to greenhouses in the desert. Paul Wootton Todays crops crisscross the globe: Mexicos tomatoes end up on your plate, our wheat heads to Africa. As a result, the challenge of growing twice as much food by 2050 to feed nine billion people—with less and less land—is everyones problem. But scientists are hard at work fomenting a second green revolution. Heres how nitrogen-spewing microbes, underground soil sensors and fruit-picking robots will help keep food on our tables. Farm the Desert 70%: Amount of the worlds freshwater used for agriculture Solution Greenhouses built near coasts turn plentiful seawater into freshwater for crops, without expensive desalinization plants. Potential Farmers could grow cash crops like lettuce and tomatoes in the desert. ETA Three pilot projects are under way, and researchers are scouting sites for a larger full-scale project. On frequent trips to Morocco, British lighting designer Charlie Paton was struck by the juxtaposition of sea and vast, sweeping desert. Youre on the edge of the Sahara but so close to the ocean, he says. After selling his lighting company, Paton set about designing something that brings the two together: the Seawater Greenhouse, a low-energy means of growing food in desert regions using abundant nearby saltwater. Three pilot greenhouses in Tenerife, the Canary Islands; Abu Dhabi, the United Arab Emirates; and Oman use prevailing winds, fans and simple evaporators to convert seawater into fresh, and in the process create a humid environment in which just about any plant can grow.The greenhouses, which will cost as little as $5 a square foot to build, get water from the sea, either by gravity or a pump. The water trickles down honeycomb-shaped lattices on the front wall and evaporates, cooling and humidifying the air inside. The air warms as it travels across the greenhouse—hotter air can hold more moisture—before reaching a second evaporator, which supersaturates it. From there, the air moves immediately into a condenser, which pulls out freshwater and sends it to an underground storage tank for watering the plants. Paton is now scouting locations for the Sahara Forest Project, which will add a concentrating solar power plant to the greenhouse concept. Extra freshwater could then be used to run the facility (the sun heats water in pipes to make steam, which drives generators) and to clean the huge arrays of mirrors.
Posted on: Fri, 26 Sep 2014 07:07:58 +0000