The blooming desert
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CTA. 1993. The blooming desert. Spore 48. CTA, Wageningen, The Netherlands.
Permanent link to this item: http://hdl.handle.net/10568/49268
Making the deserts bloom may soon be more than just a dream. Researchers at the Scottish Agricultural College have developed a hydrogel, a water-retentive swelling gel, which makes it possible to grow crops and trees in arid areas where saline...
Making the deserts bloom may soon be more than just a dream. Researchers at the Scottish Agricultural College have developed a hydrogel, a water-retentive swelling gel, which makes it possible to grow crops and trees in arid areas where saline water is a problem. The hydrogel, based on polyethylene oxide, has been developed with the University of Strathclyde. It has three distinct uses: firstly, it can be used to coat seeds before planting in soils where saline water may be a problem. This coating allows moisture through but 'filters out' the salt which would destroy the seedling. The hydrogel can also catch and retain water from mist and fog that sweeps over deserts in the cool nights. A second use for the hydrogel is to mix it with soil when planting trees. If the hydrogel is saturated at planting, then moisture will be gradually released over a period of time. Eventually the hydrogel will degrade by which time the roots will be established. The hydrogel can be used also for growing vegetables in soil-less cultures. lt allows tomatoes and cucumbers to be grown with water as saline as 16.()()0ppm (seawater contains roughly 35,000 ppm and freshwater less than 1 25ppm). It is possible to combine the hydrogel with a unique valve which opens when the hydrogel is dry and closes when sufficient water has been fed to the surrounding crop: the valve requires no electricity. Dr R Szmidt Scottish Agricultural College Auchincruive Ayr Scotland KA6 5HW UK