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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.数据集概览 本数据集涵盖中国东北黑土区不同坡度梯度与土壤管理措施下，土壤团聚体稳定性及土壤有机碳（soil organic carbon, SOC）空间再分布的实验数据，阐明了物理阻隔措施对坡耕地土壤侵蚀与碳运移的影响机制。 1. 实验设计与方法 本研究在吉林省长春市青沟小流域的径流小区内开展，采用完全交叉实验设计： 处理组：秸秆沟覆（S）与无覆盖对照组（CK）；坡度梯度：3°、6°、9°；坡位：上坡（U）、中坡（M）、下坡（L）。 数据集包含水稳性团聚体组分（>0.25 mm大团聚体、0.053~0.25 mm微团聚体、<0.053 mm粉粒与黏粒）及其对应的有机碳含量（SOC_M、SOC_u、SOC_S&C），并计算得到团聚体破坏率（percentage of aggregate destruction, PAD）、平均重量直径（mean weight diameter, MWD）与几何平均直径（geometric mean diameter, GMD）等物理参数。所有测定均设置3次独立重复（n=3），共计54条数据记录。 2. 核心研究发现 1. 秸秆沟覆将均匀土壤侵蚀转变为选择性泥沙搬运过程； 2. 9°陡坡会因累积阻隔效应，在坡地下位区域引发显著的SOC沉积； 3. 覆垄措施仅在易沉积区域提升水稳性团聚体稳定性，具体表现为PAD降低、MWD与GMD升高； 4. 大团聚体是坡地SOC空间再分布的主要载体； 5. 该系统中SOC的固存依赖物理滞留机制，而非直接的碳输入。 3. 数据解读与使用指南 样本命名规则：形如"9°S-L"的标签中，数字代表坡度（9°），"S"表示秸秆沟覆（无"S"则为对照组CK），末尾字母代表坡位（上坡、中坡或下坡）。 归一化说明：三类团聚体组分（大团聚体、微团聚体、粉粒与黏粒）的质量占比总和为100%。若用户需可视化该数据（如堆叠柱状图），应将原始质量值转换为相对百分比。 空间动态特征：陡坡下坡位（L）的高SOC与大团聚体含量表明此处为沉积汇，该区域的物质来自上坡剥离的泥沙，而非侵蚀程度较低。