Date

Overview
This dataset contains experimental data on soil aggregate stability and the spatial redistribution of soil organic carbon (SOC) under varying slope gradients and soil management practices in the black soil region of Northeast China. It elucidates how physical barriers influence soil erosion and carbon transport on sloping farmlands.
1. Experimental Design & Methods
Conducted in runoff plots within the Qinggou small watershed (Changchun City, Jilin Province), the study used a fully crossed design:
Treatments: Furrow straw mulch (S) vs. No mulch/Control (CK).
Slope Gradients: 3°, 6°, and 9°.
Hillslope Positions: Upper (U), Middle (M), and Lower (L).
Data includes water-stable aggregate fractions (macroaggregates >0.25 mm, microaggregates 0.053–0.25 mm, silt and clay <0.053 mm) and their associated SOC content (SOC_M, SOC_u, SOC_S&C). Calculated physical parameters include percentage of aggregate destruction (PAD), mean weight diameter (MWD), and geometric mean diameter (GMD). All measurements include three independent replicates (n=3), totaling 54 data rows.
2. Key Findings
Furrow straw mulch shifts uniform soil erosion to selective sediment transport.
Steep slopes (9°) drive significant SOC deposition at lower hillslope positions due to cumulative blocking effects.
Mulch enhances water-stable aggregate stability (decreased PAD, increased MWD and GMD) specifically in sedimentation-prone zones.
Macroaggregates act as the primary carrier for redistributed SOC across the hillslope.
SOC conservation in this system relies on physical retention mechanisms rather than direct carbon input.
3. Data Interpretation & Usage Guidelines
Sample Labels: In labels like "9°S-L", the number denotes the slope (9°), "S" indicates furrow straw mulch (absence means CK), and the final letter denotes the position (Upper, Middle, or Lower).
Normalization: The mass proportions of the three aggregate fractions (Macro, Micro, Silt & Clay) sum to 100%. Users visualizing this data (e.g., stacked bar charts) should normalize the raw mass values to relative percentages.
Spatial Dynamics: High SOC and macroaggregate values at the lower positions (L) on steep slopes indicate depositional sinks. These represent trapped sediment detached from upper positions, not a lack of erosion.