As global economies fell into the grip of COVID-19 lockdowns a remarkable and transformative phenomenon was drawing to a close in a secluded segment of the United Arab Emirates. Within just 40 days, a once barren tract of desert sand in this landlocked nation was teeming with sweet, ripe watermelons radiating beneath the Arabian sun.

This marked a striking milestone for a country that relies on importing nearly 90% of its fresh produce. What used to be a harsh, sterile Arabian desert was becoming a fertile fruit farm, thanks to a seemingly simple blend of clay and water. Cultivating these fruitful melons was feasible only due to the marvel of liquid nanoclay. This soil recovery solution traces its origin about 1,500 miles west, two decades ago.

In the 1980s, parts of the prolific Nile Delta in Egypt, known for its fertility despite its proximity to the arid desert, started to desiccate. Its vitality faded within a mere decade despite millennia of bountiful yields. In the late summers, the Nile would overflow, spreading over the Egyptian delta plains before receding. Scientists, trying to understand the reason behind the drop in fertility, realized that these floodwaters carried minerals, nutrients, and vitally clay particles from the East African drainage basin, nourishing the delta lands. But this essential serving was no longer present.

The construction of the Aswan Dam across the Nile in southern Egypt during the 1960s, an extraordinary 2.5 miles wide structure meant to stimulate hydroelectricity production and modulate flooding for easier farming, had also inadvertently curbed the flow of these nourishing elements.

Having discovered the problem, soil scientists and engineers, most notably Ole Sivertsen, CEO of Desert Control, sought to find a solution. Just as we see in our gardens, the presence of clay can significantly alter the nature of thin, fragile soils. Leveraging this concept, Desert Control planned to utilize nanoclay to transfigure the unproductive desert land “from sand to hope.”

Although using clay to enrich soils is a longstanding practice, traditional methods involving heavy clay have been labor intensive, environmentally damaging, and disruptive to underground ecosystems. Present-day methods require a careful balancing act, as too little or too much clay can lead to ineffective or even detrimental impacts, a challenge fluid dynamics engineer Kristian P Olesen worked for years to reconcile.

Applying decades of research, the team perfected a thin, balanced liquid formula to seamlessly penetrate through tiny local soil particles, binding instead of seeping out and draining away. The optimized, target soil stratum that sits in and below the root zone of most crops, ideally around 10-20cm (4-8in) of soil, benefits the most from this treatment.

When combining sand and clay, soil chemistry plays a significant role. Clay particles, with a negative charge attract positive charged sand grains, resulting in a perfect bond as a thin layer of clay envelopes each sand particle, enhancing the surface area and enabling better retention of water and nutrients.

After nearly 15 years of development, with the past 12 months focused on commercial scaling following independent testing by the International Center for Biosaline Agriculture (ICBA) based in Dubai, this fascinating technology is finally ready to reinvigorate farmlands at unprecedented scale.

“Now that we have scientific evidence for effectiveness, we aim to build numerous mobile mini-factories in 40ft (13m) shipping containers with the ultimate aim of creating as much change as we possibly can,” says Ivertsen. “These mobile units will create liquid nanoclay local to where it is required, using clay from the same country, and hiring regionally.”

The first of these factories will be capable of producing 40,000 litres of liquid nanoclay per hour and will be put to use in city parklands in the UAE, as the tech can reduce water use by up to 47%.

Current start-up costs fall around $2 (£1.50) per square metre, which is acceptable for small farms in the affluent UAE, but to have an impact where it really matters – in sub-Saharan Africa – Sivertsen needs to work out how to lower that number.

With scale, they can drive that cost down, ultimately aiming for around $0.20 (£0.15) per square metre. Sivertsen says that the cost of buying productive agricultural land elsewhere in the world ranges from $0.50 to $3.50 (£0.38 to £2.65) per square metre. In the future, it might be significantly cheaper to transform unproductive land than to seek out an established farm. The treatment lasts about five years, after which the clay needs a top-up.

“Beyond that, we are working with the United Nations Convention to Combat Desertification to support the Great Green Wall Project, an initiative to build a wall of trees and agroforestry to stop the expansion of the desert in North Africa,” says Ivertsen.

While infusing clay into the sandy soils of areas such as North Africa and the Middle East breaks new ground, what about the rest of the world? Globally, soils have lost 20 – 60% of their organic carbon, and nanoclay is only suited to lift sandy soils out of regression. If you are working with salty, non-sandy soils, biochar may be your friend.

This stable form of carbon is produced by burning organic matter through pyrolysis, producing hardly any pollutants as oxygen is kept out of the combustion process. The charcoal like substance is highly porous, lightweight, and with a vast surface area. It is just what depleted soils need.

The organic content of soil is always evolving, but a base level of stable carbon is present in a healthy soil. Unlike how organic matter is constantly and rapidly turned over by microbial activity, biochar is stable carbon that helps the soil hold onto nutrients crucial to plant growth. It offers a fast-track way of introducing that stable carbon element, which would otherwise take decades to develop.

Biochar can facilitate plant growth through recovering the soil structure, especially in association with other organic matter, including the addition of compost. This can help restore land that lacks organic matter due to over-farming or those affected by mining or contamination, provided the toxicity is dealt with first.

Other soil recovery techniques include using vermiculite, a phyllosilicate mineral mined from rocks and treated with heat so that it expands. The spongy nature of the resulting material allows it to absorb three times its weight in water and retain it for long periods. Meanwhile, highly absorbent polymer beads can be placed in the root zone of individual plants, allowing for water uptake beyond their weight for short periods. However, both require soil cultivation for placement, which has its downsides.

Back in the UAE, communities living nearby have already benefited from the ability to turn the desert around them into fertile land. The arrival of the produce grown using nanoclay proved serendipitous as Covid-19 lockdown restrictions came in. Around 200kg (440lb) of watermelons, zucchini, and a crop of pearl millet were produced in the 0.2 acre (1,000sq m) trial plot.

“Lockdown in the UAE was very strict, and their imports plummeted, meaning fresh produce was unavailable to many,” says Ivertsen. “We worked with ICBA and the Red Crescent team to get the fresh watermelons and zucchini to individuals and families nearby. The aim was to test it all for the higher nutrition levels we suspect crops grown under such conditions may provide, but that will have to wait for the next trial plot.”