Performance of Artificially Transplanted Biocrusted Soil-surfaces in Rainwater Harvesting and Their Capability to Resist Erosion in the Hilly Region of Chinese Loess Plateau

Abstract

[Objective] The purpose of the study was to explore the rainwater harvesting effect and erosion damage resistance of different types of artificial biocrusted soil surfaces in the hilly region of Chinese Loess Plateau. [Methods] The biocrusted soil surfaces were taken as the research object, and the bare soil surfaces as the control. The study conducted field simulated rainfall and erosion resistance experiments (slope scouring, soil disintegration, and single raindrop splash erosion experiments) on them, respectively. Differences in the erosion resistance among different types of soil surfaces were analyzed. [Results] (1) Biocrusted soil surfaces significantly improved rainwater harvesting efficiency. At a rainfall intensity of 100 mm/h, the rainwater harvesting efficiency of the biocrusted soil surfaces was significantly increased by 33.3% compared to bare soil (F = 300.12, p < 0.001). (2) Biocrusted soil surfaces significantly reduced the sand production and increased the coefficient of erosion resistance. Compared with bare soil, the sand production of cyano and moss biocrusted soil surfaces was reduced by 178.8% and 364.6%, respectively. Compared to bare soil, moss and cyano biocrusts had 4.6 and 2.8 times, respectively, the maximum coefficients of resistance to washout. (3) Biocrusts significantly reduced the soil disintegration rate and maximum disintegration rate, and the differences were significant. Compared with bare soil (6.46 g/min), the disintegration rates of cyano and moss biocrusts were reduced by 35.0% and 60.2%, respectively and the maximum disintegration rate of biocrusts was reduced by 23.8%. (4) Biocrusts significantly increased the raindrop kinetic energy and reduced soil spallation. The critical kinetic energy of moss and cyano biocrusts was 3.9 and 21.9 times higher than that of bare soil (0.5 J), respectively. Meanwhile, the soil splash erosion of the biocrusts was reduced by 75.3% on average compared to bare soil (0.156 g). [Conclusion] Biocrusted soil surfaces significantly improved the erosion resistance and rainwater harvesting effect, which is of great significance in terms of sustainable utilization and soil and water conservation in dry areas.

Keywords

• biological soil crusts
• rainfed afforestation
• soil and water conservation
• ecological restoration
• soil erosion