Agri Kultuur July / Julie 2018 | Page 7

equivalent of “three to five acres of farmland”, using 97% less water through water recapture and harvesting the evaporated water through the air conditioning. As of December 2017, the TerraFarm system was in commercial operation. Interesting points to consider are that plants can exploit light that varies in intensity through the day. Controlling light governs the growth cycle of the plant. e.g., infrared LEDs can mimic 5 minutes of sunset, stimulating some plants to begin flowering. Technology Lighting engineers at Philips have demonstrated LEDs with 68 per cent efficiency. Energy costs can hence be reduced because full-spectrum white light is not required. Instead, red and blue or purple light can be generated with less electricity. A single container used for vertical gardening. Note the extended roof which allows natural lighting. Eugene Kim Urban Farmers Box https://www.flickr.com/photos/eekim/6144496634 emerged in 1999 at Columbia University and promotes the mass cultivation of plant life for commercial purposes in skyscrapers. Stackable shipping containers Several companies have developed stacking recycled shipping containers in urban settings such as: • The creation of complete off-grid container systems. • “Leafy green machine systems” a complete farm-to-table system outfitted with vertical hydroponics, LED lighting and intuitive climate controls built within a 12 m × 2.4 m shipping container. • Podponics built a vertical farm in Atlanta consisting of over 100 stacked “growpods” while a similar farm is under construction in Oman. • Some offer a proprietary system of 40- foot shipping containers, which include computer vision integrated with an artificial neural network to monitor the plants remotely . It is claimed that the TerraFarm system “has achieved cost parity with traditional, outdoor farming” with each unit producing the AgriKultuur |AgriCulture History In 1915, American geologist Gilbert Ellis Bailey used the concept of tall multi-story buildings for indoor cultivation One of the earliest drawings of a tall building that cultivates food was published in Life Magazine in 1909. The reproduced drawings feature vertically stacked homesteads set amidst a farming landscape. Dickson Despommier is a professor of environmental health sciences and microbiology. He reopened the topic of VF in 1999 with graduate students in a medical ecology class. He speculated that a 30-floor farm on one city block could provide food for 50,000 people including vegetables, fruit, eggs and meat, explaining that hydroponic crops could be grown on upper floors; while the lower floors would be suited for chickens and fish that eat plant waste. Although much of Despommier’s suggestions have been challenged from an environmental science and engineering point of view, Despommier successfully popularized his assertion that food production can be transformed. Critics claimed that the additional energy needed for artificial lighting, heating and other operations would outweigh the benefit of the building’s proximity to the areas of consumption. Despommier originally challenged his class to feed the entire population of Manhattan (about 2,000,000 people) using only 5 hectares (13 acres) of rooftop gardens. The class calculated that rooftop gardening methods could feed only 2 percent of the population. Unsatisfied with the results, Despommier made an off-the-cuff suggestion of growing 7