Great Green Wall: Drought-resilient algae to help reclaim 6,667 hectares of desert

Chinese researchers have developed an innovative geoengineering technique using drought-resilient blue-green algae (cyanobacteria) to reclaim desert land by creating a stable biological soil crust. This method, pioneered at the Shapotou Desert Experimental Research Station in Ningxia, involves deploying specially selected cyanobacterial strains embedded in nutrient-rich "solid seed" blocks. These blocks, once spread across barren dunes, activate upon rainfall, secreting a biomass matrix that binds sand particles, immobilizes shifting dunes, and forms a nutrient-rich substrate conducive to plant growth. This approach drastically reduces the natural formation time of desert crusts from 5–10 years to just one year. The project aims to reclaim up to 6,667 hectares in Ningxia over five years and is part of China’s broader “Great Green Wall” initiative to combat desertification by addressing the root cause—shifting sands—rather than relying solely on tree planting. The technology is low-cost, scalable, and has potential applications beyond China, with