What does it take to turn sand into soil capable of supporting a crop?
The answer is not simply adding more water. It is changing what happens to that water once it reaches the ground.
That was the problem being tackled by Desert Control in the United Arab Emirates. Its Liquid Natural Clay technology attracted international attention after crops including watermelon, zucchini and pearl millet were grown on land that had previously been barren sand.
BBC's Follow the Food documented how one UAE plot was transformed in a matter of weeks, while CNN examined the same technology as a possible tool for increasing agricultural production and food security in arid regions.
The photographs naturally attract attention: green leaves and watermelons growing against a desert backdrop are difficult to ignore.
But for us, one of the most interesting parts of the story was underground.
Why sand makes agriculture difficult
Sand has large particles and large spaces between them. Water can therefore move through sandy soil very quickly.
For agriculture, that creates an obvious problem. Irrigation water may travel below the active root zone before plants have had enough time to use it. Nutrients can move with it, increasing the resources required to maintain a productive crop.
Adding more water is not necessarily the answer. If the soil itself cannot retain that water effectively, simply increasing irrigation can increase losses.
Desert Control approaches the problem by changing the physical characteristics of the root zone.
Its Liquid Natural Clay consists of clay and water processed into a liquid that can be applied directly to sandy ground. According to Desert Control, the microscopic clay particles attach to sand grains and increase the surface available to retain water and nutrients.
BBC described this as creating a thin clay structure around individual sand particles. Rather than excavating the ground and mechanically mixing large amounts of clay into it, the liquid treatment can move through the existing soil.
Changing the soil is one thing. Measuring the change is another.
A healthy crop is a powerful result, but it does not tell you everything about why the system worked.
How long is water remaining available after irrigation? How does the treated soil behave through the root zone? Does the behaviour remain consistent as conditions change?
Those questions are why soil sensing matters.
As part of Desert Control's work, Pycno Terra soil sensors were used together with Deep Orbital technology to provide a continuous monitoring layer alongside the land-restoration technology.
The deployment used the 4G version of the Terra sensor in its 60 cm configuration. This provided a way of following conditions through the soil profile rather than assessing the project only from the surface.
Why depth matters
When irrigation reaches a field, the important question is not simply whether the surface becomes wet.
The important question is what happens next.
Water that remains within the active root zone can contribute to crop growth. Water that rapidly moves deeper than the roots may be considerably less useful to the plant.
A soil profile therefore tells a much richer story than a single observation at the surface.
For a technology designed specifically to improve water retention in sandy soils, that distinction becomes particularly important. Measurements through the soil profile can provide evidence of how irrigation behaves after treatment and how long useful conditions remain around the roots.
From spectacular demonstration to repeatable process
The early Desert Control trials produced the kind of result that makes a compelling photograph.
BBC reported that around 200 kg of watermelon, zucchini and pearl millet was produced from a roughly 1,000 square metre trial plot. The publication also reported Desert Control's claim that its technology could reduce water use by up to 47%.
CNN similarly reported Desert Control's claims around substantial reductions in water use and the ability to prepare treated sandy land for planting within hours.
Those are significant claims, particularly in countries where water scarcity and food security are closely connected.
But scaling an agricultural technology requires more than a successful demonstration.
It requires evidence that can be collected repeatedly across different soils, crops, irrigation systems, climates and seasons.
That is where connected soil sensing adds value.
Instead of asking only:
"Did crops grow?"we can begin asking:
"What changed in the soil, how did that change affect irrigation, and can the same behaviour be reproduced somewhere else?"A different way to think about agricultural IoT
Sensors are sometimes discussed as if installing them is itself the solution.
It isn't.
In this project, the innovation responsible for transforming the sandy soil was Desert Control's technology. The role of Pycno Terra and the surrounding Deep Orbital technology was to make part of that transformation observable.
That is an important distinction.
The best agricultural sensing systems do not exist simply to produce dashboards. They provide measurements that help people understand a physical process that would otherwise be difficult to see.
In a normal farm that process might be irrigation, root development or soil drying.
In this case, the process was considerably more ambitious: converting highly permeable desert sand into a growing environment capable of supporting crops.
From sand to evidence
Desert Control describes its ambition as turning sand into productive land.
For us, the project demonstrates a parallel idea.
When new agricultural technologies are combined with continuous measurement, a field trial becomes more than a before-and-after photograph. It becomes a dataset.
And every additional dataset makes it possible to understand a little more about how agriculture can work in places where conventional farming has historically been extremely difficult.
Background: Desert Control's Liquid Natural Clay technology and UAE trials were covered by BBC Future's Follow the Food and CNN in 2020.
Links:
https://www.bbc.com/future/bespoke/follow-the-food/the-spray-that-turns-deserts-into-farmland.html
https://edition.cnn.com/2020/08/13/world/desert-control-liquid-nanoclay-spc-intl/index.html
