Sample information for 180 surface soils (top 0-5 cm) collected from across North Carolina (USA) for 15PNIJ-21-GG-02711-SLFO.

In this National Institute of Justice funded grant, two types of surface soils representing scenarios that would potentially benefit the most from new quantitative methods were collected from across the state of North Carolina (USA) in April 2022: a) similar inorganic content but with distinct land use (category type = mineral rich), and b) those with limited inorganic content but recognizable organic fractions (category type = organic rich). At each location (n, 30), samples were collected from paired sites &lt;500 meters apart (A and B). At each paired site, three sub-site samples were collected 1 meter apart to assess method reproducibility, accuracy and small-scale variation that might be realistically observed in questioned-to-known (Q-to-K) comparisons (total n, ~180). Each sample was subjected to examination using methods currently used in practice (<i>e.g.,</i> manual color determination, polarized light microscopy, x-ray diffraction), along with three new quantitative methods: 1) instrumental colorimetry, 2) automated scanning electron microscopy energy dispersive X-ray spectroscopy of soil minerals, and 3) DNA metabarcoding of plant, bacteria, arthropods and fungi.

在美国国家司法研究所资助的项目中，2022年4月于美国北卡罗来纳州各地采集了两种表层土壤样本，它们代表了最可能从新型定量方法中获益的场景：a) 无机含量相似但土地利用类型不同（类别：富矿物质）；b) 无机含量有限但含有可识别有机组分（类别：富有机质）。在每个采样点（共30个），从相距小于500米的配对站点（A和B）采集样本。每个配对站点采集3个相距1米的子样本，以评估方法的重现性、准确性，以及在可疑样本与已知样本（Q-to-K）比较中可能实际观察到的小规模变异（总样本数约180个）。每个样本均采用当前实践中使用的方法（如手动颜色测定、偏光显微镜、X射线衍射）及三种新型定量方法进行检测：1）仪器比色法；2）土壤矿物的自动扫描电子显微镜能量色散X射线光谱法；3）植物、细菌、节肢动物和真菌的DNA宏条形码技术（DNA metabarcoding）。