You’ve read about water-saving; now see the film
Hydrogel film as an efficient alternative to drip feed and hydroponics
Film farming is a technology in which plants are cultivated on a hydromembrane composed of water-soluble polymer and hydrogel. It can reduce water consumption by up to 90%, fertiliser use by up to 80%, and help produce nutritious crops all year round.
Film Farming requires less water than current technologies such as hydroponics and soil drip culture. Unlike a hydroponics solution, roots do not come into direct contact with the culture medium (so plants cannot suck excessive water from the medium) and there is no wastage (a huge amount of medium culture is discarded in hydroponics after every production cycle). Drip soil culture needs a huge amount of water as the plants grow roots deep into the soil, and most of this supplied water is lost through leaching and evaporation (in Film farming the leaching of water supplied from the drip tubes is completely blocked by placing plastic sheets below the drip tubes, with a saving of over 95% of water in Japanese facilities).
In Film Farming roots take water and nutrients from the film absorbed by the hydrogel contained in the film by osmotic shift producing sugars and amino acids. Also, the water does not move across the film. So plants grow a thin flat sheet of roots on the film; this not only prevents evaporation but prevents sucking of excessive water by plants from the culture medium.