Durability of biotechnologically induced crusts on sand against wind erosion

Abstract Crusts on soil surfaces are well recognized for wind erosion control in arid regions and mine tailings. In the last two decades, the use of microorganisms for crust formation on the soil surface has been developed. The topic here is to examine the durability of a biocrust created by Microcoleus vaginatus cyanobacterium and a biocemented sand crust induced by precipitation of calcium carbonate by Bacillus subtilis against wind erosion. To this aim, the crusts were subjected to three wind velocities and one sandblasting condition for three different periods in wind tunnel simulation. Also, the strength of the crusts was measured after each period of sandblasting by a penetration test. The results suggested that the biocemented sand crust has a comparatively stronger bonding and more coherent structure so that its strength did not change in sandblasting in contrary to that of the cyanocrust. Concerning the crusts' erodibility, the biocemented sand crust was more durable than the cyanocrust, and its erosion was not progressive at any conditions.