Soil structure is closely linked to biological activities. However, identifying, describing and quantifying soil aggregates remain challenging. X‐ray micro computed tomography (X‐ray μCT) provides a detailed view of the physical structure at a spatial resolution of a few microns. It could be a useful tool to discriminate soil aggregates, their origin and their formation processes for a better comprehension of soil structure properties and genesis. Our study aims to (a) determine different X‐ray μCT‐based aggregate parameters for differentiating earthworm casts belowground (earthworm aggregates) from aggregates that are not formed by earthworms (non‐earthworm aggregates), and (b) to evaluate if these parameters can also serve as specific “tomographic signatures” for the studied earthworm species. For this purpose, we set up a microcosm experiment under controlled conditions during 8 weeks, including three species of earthworms tested separately: the epigeic Lumbricus rubellus, the anecic Lumbricus terrestris and the endogeic Allolobophora chlorotica. Our results show that X‐ray μCT analysis helps distinguish earthworm aggregates from non‐earthworm ones using (a) the relative volume of the components within aggregates and (b) the volumetric mass of aggregates and their global volume. In particular, the volume ratio of mineral grains within the aggregates is significantly different according to earthworm species. So, X‐ray μCT is a powerful and promising tool for studying the composition of earthworm casts and their formation. However, future research is needed to take into account the shapes and spatial distribution of the aggregates' components, in particular the different states of organic matter decomposition.

中文翻译：

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使用X射线微计算机断层扫描来表征worm来源的地下土壤团聚体

土壤结构与生物活动密切相关。但是，识别，描述和量化土壤团聚体仍然具有挑战性。X射线微计算机断层扫描（X射线μCT）以几微米的空间分辨率提供了物理结构的详细视图。它可能是区分土壤团聚体，其起源和形成过程的有用工具，以更好地理解土壤的结构特性和起源。我们的研究旨在（a）确定不同的X射线基于μCT的聚集参数，以区分地下not（非聚集体）和非formed形成的聚集体（ear聚集体），以及（b）评估这些参数是否也可以作为研究earth物种的特定“断层特征”。以此目的，风轮虫（Lumbricus rubellus），食欲的陆Lu虫（Lumbricus terrestris）和内生的绿变绿变绿藻。我们的结果表明，X射线μCT分析可使用（a）骨料中各组分的相对体积和（b）骨料的体积质量及其总体积来帮助区分earth骨和非ear骨。特别地，聚集体中的矿粒的体积比根据species的种类而显着不同。因此，X射线μCT是研究worm模型及其组成的强大而有前途的工具。但是，未来的研究需要考虑到骨料成分的形状和空间分布，特别是有机物分解的不同状态。