Saudi Arabia’s new soil technologies offer breakthrough in desert restoration

As Saudi Arabia pursues an ambitious target to restore 40 million hectares and plant 10 billion trees, researchers at King Abdullah University of Science and Technology (KAUST) say newly engineered soil technologies could turn desert restoration into a carbon-negative process from day one. Prof. Himanshu Mishra, co-founder of Terraxy and leader of the KAUST team, highlighted field results showing that CarboSoil-treated plots achieved net carbon sequestration while untreated plots were net carbon emitters.

"What gives me hope is that we now understand the chemistry of why desert soils fail, and that understanding points directly to solutions," Mishra said. "With the right soil amendment, desert greening can be carbon-negative from day one. The science is ready."

Mishra and his team identified nutrient retention under alkaline conditions as a primary bottleneck for plant growth in irrigated desert soils. That insight led to Carboil — branded CarboSoil — an engineered biochar produced from organic waste streams such as poultry manure, date palm fronds and agricultural residues. The biomass is pyrolysed into biochar and then subjected to a proprietary treatment that lowers pH toward neutral and enriches the material with slow-release phosphorus and essential micronutrients, making it compatible with alkaline sandy soils.

Key trial data underpin the claim: a two-year field trial involving 580 native acacia trees showed that plots amended with CarboSoil sequestered net carbon, while untreated plots emitted more carbon than the trees captured due to irrigation and fertilizer-related emissions. CarboSoil, when incorporated into sandy soils at 5 to 10 percent by volume, acts as a reservoir for nutrients and water and can remain effective for centuries — unlike peat moss or compost, whose benefits degrade rapidly under harsh conditions.

How the technologies work

• CarboSoil: an engineered biochar adjusted for alkaline soils; improves nutrient retention and increases biomass by up to 68 percent in trials.
• SandX: a biomimetic mulch of sand grains coated with a nanoscale biodegradable wax that reduces evaporative water loss by up to 80 percent when applied as a one-centimeter layer.
• Waste valorisation: Saudi Arabia produces more than 20 million tonnes of organic waste annually, feedstock for biochar production.

The team also challenged common assumptions about desert agriculture. Trials showed that water-focused amendments such as hydrogels and superabsorbent polymers did not significantly increase plant growth when irrigation and fertilization levels were constant. In contrast, CarboSoil improved biomass by as much as 68 percent, signaling that improving soil function and nutrient holding capacity can be more decisive than increasing water inputs alone.

Development and deployment of these technologies are supported by KAUST and industry partners including Saudi Aramco, Neom and King Salman Park. The regional Middle East Green Initiative’s goal to plant 50 billion trees across the region provides an overarching context for scaling such soil interventions.

Looking ahead, Mishra and collaborators see a pathway to large-scale landscape restoration that also contributes to durable carbon removal. By converting organic waste into long-lived carbon in soils, the approach aims to reduce landfill emissions, cut fertilizer dependence, and improve crop health — offering governments and land managers a toolset for restoring degraded rangelands across Saudi Arabia and the wider Middle East and North Africa region.