Effect of Biochar on Desert Soil Wind Erosion Using Sweep Model and Vis-Nir Spectroscopy Technique

Wind erosion is an important factor causing land degradation in a desert ecosystem. Although biochar has great potential to improve the quality and erosion resistance of soil, it is uncertain whether biochar can reduce wind erosion in desert soil. Soil samples from the 75 test plots were taken, with the application of five biochar dosages (wt%: 0, 0.5%, 1%, 2%, and 4%) and three grain sizes (0–0.25, 0.25–1, and 1–2 mm). PM 10 , suspension loss (SL), slat/creep loss (SCL) and total soil loss (TSL) were simulated by the SWEEP model. Potential of Vis-NIR spectroscopy in predicting the soil physical stability index (St), soil erodible fraction (EF), and soil aggregate geometric mean diameter (GMD) were evaluated using partial least squares regression (PLSR). With the increase of biochar dosage and/or decrease of biochar particle size, St and GMD increased. In contrast, EF, STL, and SCL decreased, indicating that both biochar particle size and biochar dosage were key parameters affecting soil wind erosion. In addition, soil specific surface area, soil organic matter content, soil cation exchange capacity, soil granular composition, and soil C/N ratio were significantly correlated with soil wind erosion. Simulated soil wind erosion indices using Vis-NIR spectroscopy in conjunction with PLSR matched well with observations (R 2 = 0.60–0.75, RPD = 1.62–2.04, RPIQ = 2.07–3.20). The pretreatment method of soil spectra also had an obvious impact on the simulations. Therefore, the combination with biochar dosage (4%) and biochar particle size ( 0–0.25 mm) was recommended to improve the wind erosion resistance of desert soil. Vis-NIR spectroscopy technique coupled with PLSR is a feasible avenue to evaluate and map soil wind erosion on a large scale.