Temporal and material variability of podzolization processes

温带和高纬度地区的灰壤以溶解的和颗粒状的有机和无机物质从表土转移到底土为特征。尽管几十年来对灰壤的形成和发展进行了深入的研究，但仍然缺乏一个全面的理论。拟议的项目旨在系统地重新评估动员和固定过程。拟议项目的目标是获得一个全面和综合的过程相关的物理和化学机制，控制的形成和发展的土壤的理解。实现这一目标的主要假设是，灰化包括一个相互作用的物理和化学过程，作为时间和土壤成分的函数。为了验证这一主要假设，将结合经典土壤分析、光谱分析、实验土壤学方法和地球化学建模，研究具有不同程度灰化作用的土壤（5种土壤，从酸性形成土到单一灰化土）。待研究的土壤将采用土壤科学方法（包括pH值、质地、CEC、氧化物含量等）进行表征。将在柱试验中用人工雨水灌溉表土，以定性和定量地描述溶解物质和颗粒物质的排放。将使用NICA-Donnan模型评价数据，以估计金属-有机络合。此外，有机和无机颗粒将在现场原位收集，随后通过红外和核磁共振光谱以及纳米二次离子质谱（NanoSIMS）进行分析。为了研究E层的形成，将用稀醋酸灌溉显示初始灰化迹象的雏形土的（E）Ah层，以再次定量和定性分析排出的溶解物质和颗粒物质。将进行矿物混合物（石英、水交换伊利石、水铁矿）和森林地面提取物的柱实验，以检查固定化过程。将形成的有机矿物协会将通过红外光谱法进行研究。与有机物发生反应的矿物将通过NanoSIMS在亚微米尺度上进行分析。最后，固定化的有机物在灰化底土将被量化和光谱合格后，物理分级的B层，从土壤中的灰化程度可变的起源。该项目的研究结果将加深对灰壤的形成、性质和动力学以及参与全球元素循环的元素（C、N、Fe、Si、Al、Mn）的认识。

Podzols of temperate and higher latitude are characterized by translocation of dissolved and particulate organic and inorganic substances from the topsoil into the subsoil. A comprehensive theory on the formation and development of Podzols is still missing, in spite of intensive research for decades. The proposed project aims at systematically reassessing of mobilization and immobilization processes. The objective of the proposed project is to obtain a comprehensive and integrative process-related understanding of the physical and chemical mechanisms that control the formation and development of Podzols. The main hypothesis to achieve the objective is that podzolization consists of an interplay of physical and chemical processes that act variably as a function of time and of the composition of soils. To test this main hypothesis, soils with varying degrees of podzolization (five soils, from an acidic Cambisol to a Haplic Podzol) will be studied in a combination of classical soil analysis, spectroscopic analyses, an experimental pedological approach and geochemical modelling. The soils to be studied will be characterized with soil-science methods (amongst others pH, texture, CEC, contents of oxides etc.). The topsoils will be irrigated with artificial rain water in column experiments to characterize the discharge of dissolved and particulate substances quantitatively and qualitatively. The data will be evaluated with the NICA-Donnan model to estimate metal-organic complexation. Additionally, organic and inorganic particles will be collected in situ in the field and subsequently analyzed by infrared and nuclear-magnetic-resonance spectroscopy together with nano secondary ion mass spectrometry (NanoSIMS). To study the formation of E horizons, the (E)Ah horizon of a Cambisol, showing signs of initial podzolization, will be irrigated with diluted acetic acid to analyze discharged dissolved and particulate substances again quantitatively and qualitatively. Column experiments with mineral mixtures (quartz, variably exchanged illite, ferrihydrite) and a forest-floor extract will be carried out to check immobilization processes. Organo-mineral associations that will have formed will be studied by infrared spectroscopy. Minerals, having reacted with organic matter, will be analyzed at the sub-micron scale by NanoSIMS. Finally, immobilization of organic matter in Podzol subsoils will be quantified and spectroscopically qualified after physical fractionation of B horizons, origination from soils with variable degree of podzolization. The findings of this project will deepen the understanding on the formation, the properties and the dynamics of Podzols and the elements (C, N, Fe, Si, Al, Mn) involved, which take part in global element cycles.