YINCHUAN, Feb. 21 (Xinhua) -- Scientists in northwestern China are releasing soil "seed" into arid desert areas to form artificial biological soil crusts, as part of efforts to stabilize dunes and create a suitable foundation for future plant growth, according to the China Science Daily.
The "seed" is solid cyanobacteria inoculum of artificial biological soil crusts developed by the Shapotou Desert Research and Experiment Station, the Northwest Institute of Eco-Environment and Resources under the Chinese Academy of Sciences. It is capable of shortening the time required for desert sand fixation from a century-long effort to an achievable three-year timeframe.
"If you spread these seeds on the desert surface, soil crusts will form when they are exposed to precipitation," said Zhao Yang, deputy head of the Shapotou station.
Cyanobacteria thrived in petri dishes, but once transplanted to the wild, they disappeared completely within less than a week because the mobile sand grains end up ripping apart the delicate cyanobacteria biofilm, Zhao said.
Inspired by natural rainfall, Zhao tried pressurized spraying. Through this method, cyanobacteria were injected into the gaps between sand grains, reducing the crust formation time from 15 years under natural conditions to merely one or two years, achieving a survival rate of over 60 percent.
This method not only avoids dehydration caused by direct sunlight but also leverages the inherent water retention capacity of the sand layer.
However, the team found that the pressurization equipment relied on electricity and accessible roads, making it impossible to implement in some areas. "Some places are inaccessible by vehicle, rendering the spraying method unfeasible," Zhao said.
To promote the application of this technique to broader desert areas and achieve its large-scale use, the research team has turned cyanobacterial crusts into solid "seeds" to facilitate transportation and sowing.
The team experimented with mixing cyanobacteria solution with organic matter and fine particles in specific proportions to create a paste-like inoculum. "The process is similar to mixing cement, requiring the optimal ratio and stirring method," Zhao said.
"The solid inoculum has not only overcome the limitations of the spraying method but also greatly enhanced the feasibility of large-scale promotion," Zhao added.
Currently, their solid inoculum has been incorporated into the new Three-North Shelterbelt Program, with an expected 80,000 to 100,000 mu (about 5,333.33 to 6,666.67 hectares) of desert to be rehabilitated in the next five years.
This innovative achievement has made a major breakthrough in desertification control, providing a Chinese solution for global desertification management. ■
