Biocrust has many ecological roles and the potential for land restoration. Major obstacles to biocrust inoculation in degraded areas are the low physical stability of soil and the frequent wet-dry cycle. Microbially induced carbonate precipitation (MICP) technology, a sand fixation technique, can increase soil stability and decrease soil evaporation. However, it is unclear what the ecological influence of MICP treatment is under the harsh environmental stress. We hypothesized that MICP-treated soil could support biocrust establishment by moderating soil disturbance and improving water retention to mitigate frequent wet-dry cycles. To verify this hypothesis, we prepared cyanobacterial biocrusts (Oscillatoria tenuis) on bare soil and on MICP-treated soil (Sporosarcina pasteurii) and cultivated them for 40 days under high- and low-frequency rainfall. We also simulated disturbance at zero, half, or equal (0, 75, and 150 kJ) the intensity of field conditions during the cultivation. Generalized linear modeling revealed that cyanobacterial biocrust with MICP treatment had high wind erosion resistance but had low indicators of biocrust growth. We also found that MICP treatment facilitated the reduction in chlorophyll content by frequent rainfall and that MICP treatment and physical disturbance had no clear interacting effects on biocrust properties. In summary, our study found MICP treatment could hinder rather than support the cyanobacterial biocrust establishment under the frequent watering and heavy disturbance. Our finding suggests that the appropriate combination of rehabilitation techniques depends on the environmental characteristics of the target area.
