Combining digital imaging, physical models and laboratory measurements is a step further towards a better understanding of the complex relationships between the soil pore system and soil functions. Eight natural 100‐cm³ soil cores were sampled in a cultivated Stagnic Luvisol from the topsoil and subsoil, which we assumed had contrasting pore systems. Artificial 100‐cm³ cores were produced from plastic or from autoclaved aerated concrete (AAC). Eight vertical holes of each diameter (1.5 and 3 mm) were drilled for the plastic cylinder and for one of the two AAC cylinders. All natural and artificial cores were scanned in an X‐ray CT scanner and printed in 3D. Effective air‐filled porosity, true Darcian air permeability, apparent air permeability at a pressure gradient of 5 hPa and oxygen diffusion were measured on all cores. The active pore system characteristics differed between topsoil (sponge‐like, network of macropores of similar size) and subsoil (dominated by large vertical macropores). Active soil pore characteristics measured on a simplified pore network, that is, from artificial and printed soil cores, supported the fundamental differences in air transport by convection and diffusion observed between top‐ and subsoil. The results confirm the suitability of using the conceptual model that partitions the pore system into arterial, marginal and remote pores to describe effects of soil structure on gas transport. This study showed the high potential of using 3D‐printed soil cores to reconstruct the soil macropore network for a better understanding of soil pore functions.

中文翻译：

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通过气体测量和CT图像评估土壤孔隙系统：使用人工，天然和3D打印的土壤核的概念研究

将数字成像，物理模型和实验室测量相结合，是朝着更好地了解土壤孔隙系统与土壤功能之间的复杂关系迈出的一步。在表层土壤和下层土壤的栽培Stagnic Luvisol中取样了八个天然的100-cm ³土壤核心，我们假设它们具有相反的孔隙系统。人造100-cm ³芯子是由塑料或高压灭菌的加气混凝土（AAC）制成的。分别为塑料圆柱体和两个AAC圆柱体之一钻了八个直径各为1.5和3 mm的垂直孔。所有天然和人造核均在X射线CT扫描仪中进行扫描，并以3D打印。在所有岩心上测量了有效的充气孔隙度，真实的达西透气度，在5 hPa的压力梯度下的表观透气度和氧扩散。活性孔隙系统的特征在表土（类似海绵，类似大小的大孔网络）和底土（主要是大的垂直大孔）之间有所不同。在简化的孔隙网络（即从人工和印刷的土壤核心）上测量的有效土壤孔隙特征，通过在表层和下层土壤之间观察到的对流和扩散，支持了空气传输的根本差异。结果证实了使用概念模型的适用性，该模型将孔隙系统分为动脉，边缘和远处的孔隙，以描述土壤结构对气体传输的影响。这项研究表明，使用3D打印的土壤核心重建土壤大孔网络的潜力很大，可以更好地了解土壤孔隙功能。