Effects of Different Precipitation Regimes on Organic Carbon Components in Biological Soil Crusts of Desert Steppe

The rainwater collected by the water reduction treatment was collected in a rainwater collection bucket, and the rainwater in the collection bucket was evenly sprayed to the corresponding water enhancement treatment area at regular intervals using a water pump and sprinkler system. In 2023, the undisturbed soil covered by biological soil crust was collected and transferred into PVC pipes subjected to natural rainfall, water increasing treatment, and water reducing treatment.

After two years of rainfall control experiments, soil samples were collected from the surface biological soil crust and underlying surface of different plots in early September 2025. Three different points were selected from each plot with different rainfall to collect soil samples. The samples were taken using the quartering method, mixed evenly, and the stones and debris on the surface of the samples were removed.

The samples were then placed in petri dishes and brought back to the laboratory. The soil thickness of the natural rainfall crust layer was 0.3-0.6 cm, the soil thickness of the water increasing crust layer was 0.5-1.0 cm, the soil thickness of the water reducing crust layer was 0.2-0.5 cm, and the soil thickness of the underlying layer was the same. Take 3-5 cm, air dry naturally, and sieve through a 2mm sieve to determine soil physicochemical properties, microbial biomass, and soil organic carbon components. Excel 2016 software was used to organize and process the data.

SPSS 26.0 software was used to perform one-way ANOVA and least significant difference (LSD) multiple comparisons on soil data from different rainfall treatments. Origin 2024 software and Canoco 5 software were used for plotting.