A validation study in Dubai demonstrates more than 70% water savings through smart soil structures in green areas, combining demand-driven irrigation with Urbanscape Green Roll growth media.
The water management specialists at RADIUS in Dubai, in collaboration with their local municipality and the greening experts at Knauf Insulation Urbanscape, conducted a six-month concept validation study. The aim was to evaluate the benefits of multi-layer soil systems incorporating Urbanscape Green Roll mineral wool growth media in combination with moisture-based irrigation control. In the field trial, which included three turf-covered comparison plots with different soil structure variants, water savings of more than 70% were achieved compared with the climatic water budget.
Water is the most important and volatile resource in the world. The demand for clean drinking water is higher today than ever. At the same time, climate change and urban expansion are placing growing long-term pressure on municipal water management systems. In many parts of the world—for example, in Central Europe—freshwater is still available in sufficient quantities. However, excessive water can also become a problem, for instance when prolonged rainfall cannot infiltrate quickly enough, leading to flooding in inhabited areas.
Green Oases in the Desert
The situation is very different in the Middle East, where immense efforts are required to supply rapidly developing regions with sufficient quantities of freshwater. A prominent example of an area with extremely high water demand is the United Arab Emirates. Consistent wastewater treatment has been one of the key approaches enabling the Emirates to transform an otherwise inhospitable desert into thriving cities and fertile oases. It is precisely here, in the heart of Dubai—the capital of the emirate of the same name—that the local company RADIUS and Knauf Insulation conducted a field trial under extreme conditions. The objective was to test concepts capable of improving the irrigation efficiency of green areas by at least 50%, while maintaining consistently healthy vegetation.
Field Trial in a Recreational Area
Parks featuring artificial lakes and green spaces for leisure time are now found in almost every district of Dubai. One of these—Al Barsha South Park in the southern part of the city—was, with the support of the municipality, adapted and equipped with test plots for the concept validation study. The vegetation in Al Barsha South Park, irrigated using treated sewage effluent (TSE), often comes under stress during the summer months due to TSE shortages. This made the park an ideal location for the trial.
Smart Surfaces
Within the park, RADIUS and Knauf Insulation established three test plots (Plots A, B, and C), each approximately 100 m² in size, with different soil structures and equipped them with advanced monitoring and irrigation technology. All three plots featured a 15 cm vegetation layer consisting of cultivated soil (“Sweet Soil”) and turf. Plots A and B were additionally equipped with 4 cm mineral wool growth media (Urbanscape Green Roll) installed beneath the vegetation layer. In Plot A, a waterproof membrane was also installed beneath the mineral wool layer. Plot C served as the control, where the cultivated soil with turf was placed directly on the sandy subsoil without additional functional layers.
To ensure objective data collection and enable demand-driven irrigation control, state-of-the-art sensor technology from Baseline (USA) was used. Soil moisture sensors were installed in each plot at depths of 10, 15, and 30 cm. These sensors provided real-time data on soil moisture directly from the root zone, enabling precise, data-driven irrigation control. In addition, the sensor system allowed for detailed tracking of water movement within the individual soil layers, as well as the effects of the growth media beneath the vegetation layer.
Expectations Exceeded
From July to December 2025, the test plots were closely monitored. Visual inspections and weekly photographic documentation ensured that the increasingly different irrigation volumes applied to the plots did not lead to any loss in turf vitality or uniformity—particularly not during Dubai’s relentless peak summer, when air temperatures exceeding 40°C are the norm rather than the exception. Alongside achieving a 50% reduction in water demand, maintaining healthy vegetation was one of the primary objectives of the concept validation study in Al Barsha South Park.
After six months, the evaluation of irrigation data exceeded the team’s expectations: intelligent, moisture-based irrigation control alone (Plot C) achieved approximately 37% water savings compared with the climatic water budget—that is, the calculated amount of water required to offset evaporation losses in this climatic zone to sustain healthy plant growth.
Significant Savings Through Mineral Wool Growth Media
Even more impressive were the results from Plots A and B. The addition of growth media fundamentally altered water demand, increasing savings to over 70%. While the control plot (Plot C) required 102.59 m³ of water (compared with a climatic water budget of 162 m³) to maintain vegetation, Plots A and B with mineral wool growth media required only 45.78 m³ (growth media without membrane) and 43.89 m³ (growth media with membrane), respectively.
Analysis of the consumption profiles also showed that seasonal variations had no significant impact on reduction. The savings were structural in nature and remained stable during both extreme summer heat and milder transitional periods.
A Water Reservoir Beneath the Roots
The underlying effect of the mineral wool growth media can be described as follows: water that percolates through the vegetated soil and is not immediately absorbed infiltrates into the Green Roll, which is less dense than the layers above and below. Here, it does not continue to drain away, but instead spreads and is stored—similar to a sponge. As surface evaporation occurs, a suction effect (capillary action) is created, allowing plant roots to draw water from the growth media.
The volume of water stored within the mineral wool layer is considerable: Urbanscape Green Roll with a dry weight of approximately 4 kg/m² can retain around 30 litres of water per m².
A Scalable Model for the Future
The conclusion of the field trial is clear: combining smart irrigation control with intelligent soil design delivers significant efficiency gains in demanding, water-scarce environments. Furthermore, mineral wool growth media alone can substantially reduce water demand, even without sensor technology or smart irrigation systems.
Scaling this solution to large green areas is straightforward and can significantly alleviate pressure in regions dependent on treated wastewater (TSE). However, the benefits are not limited to arid climates. In temperate regions, irrigation requirements can also be reduced through intelligent soil design.
At the same time, the high water retention capacity of mineral wool systems offers additional advantages: buffering heavy rainfall, supporting controlled infiltration, and helping to mitigate local flooding. This is an aspect that is becoming increasingly important in Central Europe as a result of climate change.