Microfluidic soil chips render optical access to the naturally opaque soil systems and enable direct investigation of microbial growth and interactions in micro-structurally and chemically controlled environments. However, chemical analyses of these interactions at high spatial and temporal resolution are still lacking. Here we propose that the use of advanced microspectroscopy techniques, namely infrared absorption, Raman scattering and synchrotron radiation based X-ray microspectroscopy, in microfluidic soil chips would make it possible to approach these phenomena. They allow monitoring biogeochemical processes in and around soil microbial cells growing in the reproducibly designed microenvironments within the chips at (sub)micrometer scale. Complementary use of several of the microspectroscopy techniques is beneficial for obtaining information about both molecular and elemental composition, oxidation states and local structure of the elements in the sample. Ultimately, we argue that microspectroscopy in microfluidic chips can lead to relevant breakthroughs in frontier research areas in soil science, such as (1) analysis of chemical responses of microbes to environmental triggers at micro-scale spatial resolution, (2) phenotypical identification and phylogenetic classification of single cells of soil microbes in situ, (3) determining spatially and time resolved effects of heavy metals and organic pollutants, including microplastics, on soils and (4) spatially resolved analysis of soil organic matter dynamics for better understanding of soil carbon storage. Tailoring the chip design to achieve optical transparency to the radiation type used by the different microspectroscopy methods is crucial to achieve this; therefore, we expect that this perspective will inspire the scientific community to use the proposed approaches and thus push both the technical development of the microspectroscopy suitable soil chips and the research frontier in soil science.

微流控土壤碎片使人们能够自然进入不透明的土壤系统，并能够直接研究微生物在微结构和化学控制环境中的生长和相互作用。然而，仍然缺乏在高空间和时间分辨率下对这些相互作用的化学分析。在这里，我们建议在微流体土壤芯片中使用先进的显微光谱技术，即红外吸收，拉曼散射和基于同步辐射的X射线显微光谱，将有可能解决这些现象。它们允许以（亚）微米规模监测芯片内可重复设计的微环境中生长的土壤微生物细胞内和周围的生物地球化学过程。几种显微技术的互补使用有利于获得有关分子和元素组成，样品中元素的氧化态和局部结构的信息。最终，我们认为微流控芯片中的显微光谱技术可以导致土壤科学前沿研究领域的相关突破，例如（1）在微观空间分辨率下分析微生物对环境触发物的化学反应，（2）表型鉴定和系统发育土壤微生物单细胞分类原位，（3）确定的空间和时间分辨的重金属和有机污染物，包括塑料微粒的作用，对土壤和（4）的空间分辨土壤有机质动力学分析为了更好的理解土壤碳存储。量身定制芯片设计，以实现对不同显微技术所使用的辐射类型的光学透明性，对于实现这一点至关重要。因此，我们希望这种观点将激发科学界使用建议的方法，从而推动适用于土壤光谱的显微技术的技术发展以及土壤科学的研究前沿。