Accelerating the formation of biological soil crusts in the newly dried-up lakebeds using the inoculation-based technique

Abstract

The disappearance of water bodies and the emergence of dry lakebeds have intensified global environmental challenges such as dust source regions and moving dunes. The rapid formation of biological soil crusts (biocrusts) in these new ecosystems can help to accelerate their sustainability. Thus, we assessed how an inoculation-based technique (IBT) could contribute to the formation of biocrusts in a simulated sandy soil profile collected from the dried region of Lake Urmia, in the northwest of Iran. To this end, a full factorial combination of native bacteria, cyanobacteria, and a combination of the two were inoculated onto an experimental soil. After 120 days, the soil surface properties were measured, and the differences between the treatments were tested. The results showed that microbial inoculation, especially cyanobacteria, accelerated the biocrusts formation and the soil surface stability. Inoculated micro-organisms improved the biocrusts indicators including carbon (225%; p < 0.01) and nitrogen (3200%; p < 0.01) content, available phosphorus (70%; p < 0.01) and potassium (19%; p < 0.05), cation exchange capacity (9.3%; p < 0.05), pH (−1.2%; p < 0.01), electrical conductivity (−23%; p < 0.01), soil moisture (15.7%; p < 0.05), bulk density (−2.5%; p < 0.05), surface roughness (34.8%; p < 0.01), and aggregate stability (133%; p < 0.01), as compared to the non-inoculated soil. Analysis of the scanning electron microscopy images obtained from the soil surface also confirmed the ability of cyanobacteria to create strong bonding between soil particles. Overall, the IBT could be considered as a fast and eco-friendly way for creating/restoring biocrusts in newly dried-up/degraded lands.