Pedogenic controls on nutrient retention and structure stability of fallow sandstone-derived soils in humid tropical environments

This dataset contains soil horizon-level data from four pedons (FL-1 to FL-4, 18 horizons total) excavated in Nkaliki, Abakaliki LGA, Ebonyi State, southeastern Nigeria, on soils derived from Ajali Sandstone parent material. The dataset supports the manuscript "Pedogenic and Structural Controls on Nutrient Retention in Coarse-Textured Sandstone-Derived Soils" submitted to Catena. Data include particle size distribution (sand, silt, clay), physical properties (bulk density, gravimetric moisture content), four computed structural and pedogenic indices (clay ratio, silt:clay ratio, complexed clay ratio, and structure stability index), soil chemical properties (pH, soil organic carbon, total nitrogen, available phosphorus, exchangeable bases, exchangeable acidity, effective cation exchange capacity, base saturation), elemental ratios (Ca:Mg, K:Mg, C:N, exchangeable sodium percentage), and available micronutrients (Zn, Cu, Mn). Particle size was determined by the hydrometer method, bulk density by the core method, and macro/micronutrients by standard wet chemistry and atomic absorption spectrophotometry. Structural indices follow established formulations (Dexter et al., 2008; Pieri, 1992). Full methodological details, units, and formulas for every variable are provided in the accompanying "Variable Descriptions" sheet. This dataset enables reproduction of the correlation, structural, and fertility analyses presented in the manuscript, and may be reused for comparative studies of nutrient retention and structural degradation in coarse-textured tropical soils.本数据集包含采自尼日利亚东南部埃博尼州阿巴卡利基地方政府区域（Abakaliki Local Government Area, LGA）恩卡利基地区4个土壤剖面（FL-1至FL-4，共18个土壤发生层）的发生层级数据，供试土壤均发育于阿贾利砂岩母质。本数据集支撑已提交至学术期刊《Catena》的论文《粗质地砂岩发育土壤养分保留的成土与结构调控机制》。 数据集包含的指标如下：颗粒粒径分布（砂粒、粉粒、黏粒）、物理性质（容重、重量含水率）、4项计算得到的结构与成土指数（黏粒比率、粉粒:黏粒比率、络合黏粒比率以及结构稳定性指数）、土壤化学性质（pH值、土壤有机碳、全氮、有效磷、交换性盐基、交换性酸度、有效阳离子交换量、盐基饱和度）、元素比率（钙（Ca）:镁（Mg）、钾（K）:镁（Mg）、碳（C）:氮（N）、交换性钠百分比）以及有效微量营养元素（锌（Zn）、铜（Cu）、锰（Mn））。 颗粒粒径采用比重计法测定，容重采用环刀法测定，大量/微量营养元素采用标准湿化学法与原子吸收分光光度法测定。结构指数遵循已有的计算公式（Dexter等，2008；Pieri，1992）。所有变量的完整方法细节、测定单位及计算公式详见配套的"变量说明"工作表。 本数据集可复现论文中呈现的相关性分析、结构分析与肥力分析结果，亦可用于粗质地热带土壤养分保留与结构退化的比较研究。