Differentiating the roles of organic nuclei and mineral surfaces in the formation of soil microaggregates by exploring their elemental and isotopic label composition

有了这个建议，我们的目标是阐明管理过程和机制，通过分析微观空间元素/同位素组成和三维协会的有机和矿物土壤成分在亚微米分辨率的土壤微团聚体的形成。我们认为，进入土壤的不同形式的有机质提供了重要的核形成的微团聚体，从而导致一个分区结构的聚集体。因此，在一个新的孵育实验中，我们将测试不同的机制微团聚体的形成，作为有机核，即溶解的有机物，颗粒状植物残留物，或微生物necromass的不同的有机物输入启动。我们还打算揭示土壤微团聚体的形成，通过应用我们的分析方法，从黄土pedosequence和研究单位的有机质耗竭现场试验的天然土壤材料。我们将特别关注NanoSIMS的分析能力，以共同定位有机物和矿物质的封存/累积，并量化它如何影响异质土壤微结构。这些空间上明确的数据将得到大规模测量的补充，例如13 C-NMR光谱，以表征有机物的化学组成。收集的数据将使我们能够确定和量化颗粒表面的不同部分对土壤结合有机碳的功能，其水储存和运输功能以及微生物栖息地的贡献。所开发的确定的机械关系将形成研究单位开发的定量模型的一个组成部分。

With this proposal we aim to elucidate governing processes and mechanisms for the formation of soil microaggregates by analyzing the microspatial elemental/isotopic composition and the three-dimensional association of organic and mineral soil components at submicron resolution. We suggest that the different forms of organic matter that enter soils provide important nuclei for the formation of microaggregates leading to a compartmentalized architecture of aggregates. In a new incubation experiment we will therefore test the different mechanisms for microaggregate formation as initiated by different organic matter inputs that serve as organic nuclei, i.e. dissolved organic matter, particulate plant residues, or microbial necromass. We also intend to reveal soil microaggregate formation by applying our analytical approach to the natural soil materials from the loess pedosequence and the organic matter depletion field trial of the research unit. We will specifically focus on the analytical power of NanoSIMS to co-localize the sequestration/accrual of organic matter and minerals and quantify how it influences the heterogeneous soil microarchitecture. These spatially explicit data will be supplemented by bulk scale measurements, such as 13C-NMR spectroscopy to characterize the chemical composition of organic matter. The data collected will enable us to identify and quantify the contribution of distinct parts of the particle surfaces for the functions of soils for binding organic carbon, their water storage and transport function and as habitats for microorganisms. The developed identified mechanistic relationships will form an integral part of the quantitative model developed in the research unit.