ON THIN AIR

Agriculture students demonstrate how aeroponics, once a niche and costly cultivation method, can help urban households

- RAJIT SENGUPTA

SOMETIME IN the late 1990s, US space agency NASA teamed up with an agro-biology company and a high-impact space life research center, both based in the US, to embark on an ambitious experiment. The aim was to grow plants aboard the Mir space station, which operated in low Earth orbit. In 1997, the team negated the fundamental agricultural requirements—soil, sunlight, and intensive water for irrigation—and successfully grew adzuki beans in microgravity. The cultivation technique, known as aeroponics, was well established in the 1940s. But it had remained largely confined to research and innovation till the NASA experiment demonstrated its potential as an effective and efficient means of growing plants anywhere. While NASA has since used the technique to successfully grow a variety of crops, including lettuce, mustard, and radishes, in space, aeroponics has also captured popular imagination here on Earth.

Aeroponics is essentially an indoor farming technique in which plants grow in a controlled environment that is free from soil or any other aggregate media. Roots hang suspended in the air while a nutrient solution is sprayed as a fine mist. Spraying is a specialized process that, through clock-work precision and factory-like settings, can imitate plant growth across multi-level chambers, which remain lit by led lights of different calibrations. Such a system does not require much land and can be set up in a vertical manner. As per NASA water usage in the system reduces by an impressive 98 per cent. Since the roots get the nutrients directly, fertilizer usage also decreases by 60 percent. Pesticides are fully eliminated, as the absence of soil reduces the chances of diseases.