Desert Control: Tackling Desertification with Clay and Water

https://www.azocleantech.com/article.aspx?ArticleID=1172

By Ben Pilkington, MSt

A low-tech, widely applicable nanotechnology solution has been developed with the potential to reverse desertification. Norwegian cleantech company Desert Control has been developing its highly effective nanoclay solution for decades. Now it can be produced commercially and at scale, potentially revolutionizing agriculture around the world.

What is Desertification?

Desertification is the degradation of drylands that become increasingly arid over time because of human activity or other environmental factors. It can be a result of overexploitation, where nutrients have been taken from the soil too quickly without allowing soil time to recover. Deforestation and prolonged periods of drought are also possible causes of desertification.

Whatever the cause, the result is the same: desert land that cannot be farmed.

Around 40% of the earth’s land area is classified as “dryland”. Of this 40%, an estimated 10-20% has degraded due to desertification. This represents between 6 and 12 million square kilometers – that is, a total area around the size of Europe and Australia combined.

The problem is growing as dryland soil conditions continue to deteriorate. Researchers now place up to one billion people at risk of further desertification in the coming years.

Nanoclay to Combat Desertification

Nanoclay was developed to tackle this global challenge. Low-tech clay has been used for millennia to improve soil conditions. Mixing it with dry soils can help them to retain more water, enabling crops planted in them to access more nutrients for healthy growth.

However, mixing heavy clay with soil is incredibly labor-intensive, hard work. Furthermore, the process exposes valuable carbon sequestered in the topsoil to the elements, causing it to be released into the atmosphere. It further harms soil systems by breaking up the fungal networks that keep plants in communion with one another and with the wider ecosystem underground.

The nanoclay solution developed by Desert Control retains the soil-improving qualities of clay applications without the harmful and labor-intensive task of mixing clay into the soil.

Nanoclay is sprayed onto the surface in a water-based solution before regular water irrigation. Nano-sized particles of a clay mixture specially selected for the local soil and conditions slip below the surface and through particles of soil to the optimum depth (10-20 cm).

Nanoclay binds to the dry soil it touches due to the negative charge carried by clay molecules and positive charge in the sandy soil molecules. This results in a clay layer around each particle of soil of around 200-300 nm in a snowflake-like formation. This increased surface area traps water in the soil and allows water and nutrients to chemically combine with the sandy soil before they run off from it.

One treatment of nanoclay can last up to five years. It can improve water retention by up to 65% and reduce the need for water irrigation by up to 47%. The treatment can also be simply performed with virtually no training or professional expertise required and using common agricultural tools.

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Author: Willem Van Cotthem

Honorary Professor of Botany, University of Ghent (Belgium). Scientific Consultant for Desertification and Sustainable Development.