Biochar increases rill erosion risk during the short term following its application to distinct loess textures
Description
The core hypothesis of this study was that short-term biochar amendment would, contrary to its long-term benefits, exacerbate rill erosion risk in loess soils by increasing soil detachment capacity (Dc) and rill erodibility (Kr), with this effect being significantly modulated by soil texture.To test this hypothesis, a dataset was established through flume experiments and soil physicochemical analyses. The first part comprises raw data from flume scour experiments. The experiments were conducted in a recirculating flume under controlled hydrodynamic conditions, combining two slope gradients (15° and 25°) with three flow discharge rates (12, 24, and 36 L min⁻¹). All experimental runs were performed following a 2-week incubation period after biochar application, during which both amended and control soils were maintained under identical open-air conditions. A total of 240 experimental runs were performed, covering five loess soils of distinct textures (from Yangling, Changwu, Ansai, Dingbian, and Shenmu) each under two treatments: untreated control and amended with 3% corn straw biochar. For each run, primary data on hydraulic parameters (flow velocity, temperature) and erosion response (dry weight of collected sediment and corresponding scouring duration) were recorded directly. These primary measurements were then used to calculate key hydrodynamic stress indicators—including shear stress, stream power, and unit stream power—applying standard hydraulic formulas. The fundamental response variable, soil detachment capacity (Dc), was subsequently determined from these calculations. The second part is the supporting soil physicochemical property dataset. This component involves standardized laboratory analyses performed on all soil samples used in the flume experiments (both control and biochar-amended). This dataset is intended to elucidate the controlling mechanisms of intrinsic soil properties on the erosion process. The dataset clearly reveals several key findings. Firstly, the data directly demonstrates that short-term biochar amendment consistently and significantly increased soil detachment capacity (Dc) across all tested soil textures and hydrodynamic conditions, and generally raised rill erodibility (Kr). Secondly, data analysis indicates that the finest-textured clay loess was the most sensitive to this biochar-induced erosion exacerbation. Most critically, the data identifies soil organic carbon (SOC) as the dominant factor controlling Dc and Kr. Finally, the data confirms that stream power (ω) serves as the optimal hydrodynamic predictor for Dc. This foundation successfully supported the development of high-fidelity multivariate predictive models that integrate hydraulic forcing (stream power) with key soil attributes (e.g., SOC, MWD, porosity).