Scientists figure out how to turn desert sand into fertile soil

 A new process which turns desert sand into fertile soil relatively quickly

China has invented a method using 3.5 billion-year-old microbes to turn desert sand into fertile soil in just 10 months. These microbes stabilize sand and protect ecosystems, allowing restoration teams to plant shrubs and grasses. The process involves spraying lab-grown cyanobacteria on straw checkerboards, which harden into a cohesive layer that prevents wind erosion. This innovation accelerates the desert restoration process, which typically takes decades, to just a few years. However, long-term protection from vehicles and heavy foot traffic is necessary to maintain the restored surface. Scientists have used lab-grown microbes to bind loose desert sand into a thin, stable layer which wind cannot easily blow away. The stronger surface gives restoration teams time to plant shrubs and grasses before harsh winds and heat wipe out young plants...crusts stabilize sand within 10 to 16 months. On straw checkerboards laid across northwest China, a dark film spread over treated sand and stayed after seasonal dust storms. Tracking those plots through heat and frost, the Chinese Academy of Sciences (CAS) documented how fast the film hardened. In trials near the Taklamakan Desert in Xinjiang in northwest China, CAS teams saw crusts stabilize sand within 10 to 16 months. Even with that speed, planners focused on building the soil base first, so later plants could survive without constant replanting.

When fertile land becomes desert, farmers are forced to leave. Fewer farms means fewer crops, which exacerbates global hunger, particularly in the poorest corners of the world. Chinese want to reverse this process. Using a technique called “desert soilization”, they are turning barren desert into productive, farmable land at an affordable cost and time. Climate change is turning more of the Earth’s land into inhospitable desert. When fertile land becomes barren, farmers cannot grow crops, meaning more hunger, particularly in the poorest parts of the world. Our solution transforms dry plains into productive pastures. We think we have found a solution to rising food insecurity. Long before forests existed, cyanobacteria, sunlight-powered bacteria which thrive in harsh places, likely appeared about 3.5 billion years ago. Using sunlight and air, many strains pull CO2 into their cells and leak the leftovers as simple organic matter. In desert soils short on fertilizer, some species perform nitrogen fixation, turning nitrogen gas into plant-ready nutrients for the crust community. Once they take hold, their living layer binds loose grains and gives the first plants a better place to root. Under a microscope, biological soil crusts, thin living layers on soil surfaces, show a mesh of bacterial threads wrapped around sand grains. To hold that mesh together, cells ooze sticky sugars between grains, and those sugars harden into a thin, cohesive layer. The crust acts like glue by holding sand grains together and helping prevent invasive plants from taking root. Footsteps, tires and hard raking can break the surface, so building crusts at scale also needs long-term protection.

Over the first year, the treated surface began holding nutrients near the top inch instead of letting dust blow away. Mixing with drifting mineral dust, dead cells and leaked sugars formed organic matter which helped trap N2 and P. As nutrients concentrated, more microbes could feed on them, and the crust community became harder to disturb. For seedlings, that change created a better starting point, but survival still depended on rain arriving at the right time. After short rains, a crusted patch kept moisture closer to the surface, while nearby bare sand dried out quickly. Rough pores and dark pigments reduced evaporation, because water stayed shaded and trapped under the thin layer. Moisture held for even a few extra days can help grasses and shrubs sprout roots before heat returns. During long dry spells, the living crust can go dormant, so results depend on climate and careful timing. Soilization mixes a water-based paste with sand and applies it to the desert surface, giving it the same physical and ecological properties as soil, with the same capacity for water and fertiliser retention and ventilation.

Wind provides the harshest test, and bare sand fails it when gusts pick up and carry grains away. After spraying cyanobacteria, bound grains stayed put because the crust linked them, so fewer particles lifted into the air. Lab tests with a manufactured crust cut wind-driven soil loss by more than 90% in controlled winds. Less blowing sand could mean fewer sandstorms and longer-lived roads, but the crust must survive traffic and grazing pressure. With time, the crust changed from mostly microbes to a mixed cover which included lichens and small moss patches. Lichens added a tougher surface, and their slow growth helped keep the crust intact during high winds and cold nights. Moss brought extra height and shade, which let tiny pockets of moisture linger and sheltered new microbes. Once those later partners arrived, the system became more stable, but damage also took longer to heal. As crops grow and roots decay, the soilized sand becomes self-sustaining. The solution is proven, with 1,130 hectares of arable land, already created in multiple locations of Ulan Buh desert, at an altitude of 1100 meters in northern China. The technique is so effective that the yield of some crops increases even up to four times. By converting desert sand into farmable land, the solution provides secure incomes to the world’s remotest communities.

Scaling this method beyond plots forces hard choices about where to spray microbes, since not every dune needs crust. Local strains often handle heat, salt and drought better than imported ones, so teams usually culture microbes from nearby deserts. Because desertification, land losing plant cover and becoming more desert-like, has many causes, crusts cannot solve overgrazing or water misuse. Without protection from vehicles and heavy foot traffic, a restored surface can crumble, and recovery may take years. Behind today’s fast trials sits a record from China which followed crust growth across 59 years of desert recovery. Using crust samples with known ages, the team compared untouched sites with plots treated with lab-grown cyanobacteria. Nutrient gains matched which microbes dominated, and adding cyanobacteria shortened a decades-long process to just years. Even in the best cases, that still meant waiting two to three years for a mature crust which resists disturbance. Fast crust building turns microbial growth into a practical tool, linking desert sand control with slower, plant-based restoration. Long-term monitoring will show whether durability, benefits and side effects hold across different deserts and climates of the world.