New technology could transform poor-quality sandy soils into high-yield agricultural land.
Through a combination of climate change, drought, overgrazing and other human activities, desertification across the world is on the march. It’s a process defined by the UN as “land degradation in arid, semi-arid and dry sub-humid regions”. Given that around 40 per cent of the Earth’s land surface is occupied by drylands – home to around two billion people – the potential for desertification to impact the planet is huge. A recent report from the Economics of Land Degradation Initiative claimed that it’s a problem costing the world as much as US$10.6tn every year – approximately 17 per cent of global gross domestic product.
The refugee crisis in Europe has highlighted the difficulties that arise when large numbers of people migrate. However, the numbers arriving from countries such as Syria, Lebanon and Eritrea pale in comparison to those that could be forced into exile by changing climate conditions. According to the UN’s Convention to Combat Desertification (UNCCD), the process could displace as many as 50 million people over the next decade.
But one Norwegian start-up is developing a technology to wage a frontline battle with desertification. Desert Control is a Norwegian company set up by Kristian and Ole Morten Olesen, alongside chief operating officer Andreas Julseth. It was recently awarded first prize at ClimateLaunchpad, a clean-tech business competition that attracted more than 700 entries from 28 countries across Europe. The product that earned Desert Control top honours was Liquid NanoClay, a mixture of water and clay that is mixed in a patented process and used to transform sandy desert soils into fertile ground.
The mixing process splits the clay particles into individual flakes and adds air bubbles on both sides of the flakes. The mix is then spread over the land and allowed to saturate down to root level – about 40-60cm deep. This requires around 40 litres of water and 1kg of clay per square metre. The treatment gives sand particles a nanostructured clay coating, completely changing their physical properties and allowing them to bind water. The process, which does not involve any chemical agents, can change poor-quality sandy soils into high-yield agricultural land.
According to Desert Control, virgin desert soils treated with Liquid NanoClay produced a yield four times greater than untreated land, using the same amount of seeds and fertiliser, and less than half the amount of water. It found that Liquid NanoClay acts as a catalyst for Mycorrhizal fungi when nourishment is available, with the fungi responsible for the increased yield.
Clay is a fundamental component of productive arable land, acting as a water-holder, providing elasticity, and allowing non-clay elements to bind to the soil. In the past, adding clay to dry land in order to improve its agricultural value has involved tilling clay into the soil. This requires large volumes of clay and substantial amounts of manual labour. The process of transforming sandy soil into fertile land can take between seven and 15 years. By comparison, Liquid NanoClay takes just seven hours to saturate into the land.
The water and clay is mixed on site using the patented process, then traditional irrigation systems such as sprinklers or water wagons are used to spread it across the sandy soil. The individual clay flakes bind to the surface of the sand particles with a Van der Waals binding, significantly increasing the ability of the soil to hold water and nutrients. The cost of treatment per hectare is US$4,800, and requires a 15-20 per cent retreatment after four or five years if the land is tilled. If the soil is untilled, the treatment lasts for longer. Converting a piece of desert the size of a rugby pitch into fertile land for this cost seems like a pretty good deal.
The performance data for Liquid NanoClay is based on field tests that were conducted at the Agricultural Research Centre (ARC) in Ismailia in Egypt. White pepper was planted in test fields containing dry sandy soil. Fields treated with Liquid NanoClay gave an additional two months of harvest, compared to the fields that were untreated. Following the initial harvest, the plants were then left without irrigation over winter and spring, when new plants were due to be sown. However, the original crops were found to be in such good condition that they could be used for another season. One additional advantage is that turning deserts into greenland lowers the surface temperature around 15°C and reduces CO2 emissions by 15-25 tons per hectare.
If Desert Control can successfully get Liquid NanoClay to market, the potential of the technology is enormous, with implications for fragile environments around the globe and the populations that inhabit them. Along with the testing that took place in Egypt, additional third-party verification is taking place at the Faculty of Natural Sciences at Imperial College London.