The biogeochemical functioning of soils (e.g., soil carbon stabilization and nutrient cycling) is determined at the interfaces of specific soil structures (e.g., aggregates, particulate organic matter (POM) and organo‐mineral associations). With the growing accessibility of spectromicroscopic techniques, there is an increase in nano‐ to microscale analyses of biogeochemical interfaces at the process scale, reaching from the distribution of elements and isotopes to the localization of microorganisms. A widely used approach to study intact soil structures is the fixation and embedding of intact soil samples in resin and the subsequent analyses of soil cross‐sections using spectromicroscopic techniques. However, it is still challenging to link such microscale approaches to larger scales at which normally bulk soil analyses are conducted. Here we report on the use of laboratory imaging Vis–NIR spectroscopy on resin embedded soil sections and a procedure for supervised image classification to determine the microscale soil structure arrangement, including the quantification of soil organic matter fractions. This approach will help to upscale from microscale spectromicroscopic techniques to the centimetre and possibly pedon scale. Thus, we demonstrate a new approach to integrate microscale soil analyses into pedon‐scale conceptual and experimental approaches.

中文翻译：

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通过实验室成像 Vis-NIR 光谱评估永久冻土土壤的复杂性

土壤的生物地球化学功能（如土壤碳稳定和养分循环）是在特定土壤结构（如聚集体、颗粒有机物质 (POM) 和有机矿物组合）的界面处确定的。随着光谱显微技术的日益普及，从元素和同位素的分布到微生物的定位，过程尺度上生物地球化学界面的纳米到微米级分析不断增加。研究完整土壤结构的一种广泛使用的方法是将完整土壤样品固定和嵌入树脂中，然后使用光谱显微技术对土壤横截面进行分析。然而，将这种微尺度方法与通常进行大体积土壤分析的更大尺度联系起来仍然具有挑战性。在这里，我们报告了实验室成像 Vis-NIR 光谱在树脂嵌入土壤切片上的使用，以及用于确定微尺度土壤结构排列的监督图像分类程序，包括土壤有机质分数的量化。这种方法将有助于将微型光谱显微技术升级到厘米甚至可能的足量级。因此，我们展示了一种将微尺度土壤分析整合到土壤尺度概念和实验方法中的新方法。这种方法将有助于将微型光谱显微技术升级到厘米甚至可能的足量级。因此，我们展示了一种将微尺度土壤分析整合到土壤尺度概念和实验方法中的新方法。这种方法将有助于将微型光谱显微技术升级到厘米甚至可能的足量级。因此，我们展示了一种将微尺度土壤分析整合到土壤尺度概念和实验方法中的新方法。