Fe-controls on soil microaggregate structure, stability, and composition

Fe 对土壤微团聚体结构、稳定性和成分的控制

• 批准号: 276972888
• 负责人: Dr. Nina Siebers
• 金额: --
• 依托单位: Arbeitsgruppe IBG-3: Agrosphäre
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2021-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/276972888?language=en
• 关键词: Fe; controls; soil; microaggregate; structure

Colloidal and nanosized organic and mineral particles are essential ingredients for soil microaggregate formation; however, their role for initial aggregate (nucleus) formation and their function as cementing agent is not well understood. With this proposal we aim to elucidate the role of colloids and nanoparticles for soil microaggregate formation, composition, and architecture. We will use a combination of state-of-the-art methods to analyze the size distribution of soil microraggregates, their building units on the low micron- to nanoscale, their total and spatial composition, as well as their architecture. Methods used include SPLITT, AF4, DLS, MALS (size fractionation) coupled to ICP-MS and OCD (total elemental composition), TEM/SEM-EDX (spatial elemental composition), or SAXS/USAXS and gas-adsorption techniques (porosity). These methods will be applied to soil samples obtained from the toposequence and to the multi-isotope labeled microaggregates isolated from soils from the central microcosm experiments. Soil microaggregates isolated from these samples will be disaggregated by physical and chemical treatments, and reaggregated to analyze the influence of subunit-characteristics on soil microaggregate formation. Obtained soil microaggregates and their subunits will be analyzed using the methods described above to reveal the nucleus of soil microaggregates, their cementing agents, OM sequestration, and the role of OM and Fe-species on aggregate formation and porosity. Porosity data will be complemented with porosity data obtained by X-ray CT for larger pores as collected by SP7. In addition, the influence of colloidal and nanoparticular composition on microbial activity will be gathered in collaboration with SP6. The obtained size distribution data of will be given to PM to help developing a mechanistic quantitative model.

胶体和纳米化的有机和矿物颗粒是土壤微聚集形成的重要成分。但是，它们在初始聚集体（Nucleus）形成及其作为胶结剂的功能尚不清楚。通过此提案，我们旨在阐明胶体和纳米颗粒在土壤微聚集，组成和建筑中的作用。我们将使用最先进的方法的组合来分析土壤微聚集物的尺寸分布，其在低微米至纳米级上的建筑单元，它们的总和空间组成及其建筑。所使用的方法包括与ICP-MS和OCD（总元素组成），TEM/SEM-EDX（空间元素组成）或SAXS/USAXS/USAXS和GAS-ADSSORPONTING ADSSORVENTION TENCERS（POROSICE）（POROSICE）（POROSICE）耦合（总元素组成），TEM/SEM-EDX（空间元素组成）（tem/sem-eDX（空间元素组成）（空间元素组成）（tem/sem-eDX），包括分布，AF4，DLS，MALS（尺寸分馏）。这些方法将应用于从座椅试验中获得的土壤样品，以及从中央缩影实验中从土壤中分离的多异构体标记的微聚集物。从这些样品中分离出来的土壤微聚集物将通过物理和化学处理分解，并重新进行了重新分析以分析亚基 - 特征学对土壤微聚集形成的影响。将使用上述方法分析获得的土壤微聚集物及其亚基，以揭示土壤微聚集核的核，其胶结剂，OM固固剂以及OM和Fe物种在聚集的形成和孔隙率上的作用。孔隙率数据将与X射线CT获得的孔隙率数据相辅相成，用于SP7收集的较大孔。另外，将与SP6合作收集胶体和纳米骨组成对微生物活性的影响。获得的尺寸分布数据将提供给PM，以帮助开发机械定量模型。