Linking the field and the atomic scales: Soft x-ray spectroscopy of soil chemical processes

当今科学面临的几个重大挑战涉及能够更好地管理地球的土壤资源：通过集约化农业可持续地养活90亿人，在气候变化的情况下保护我们的水资源，有效地恢复和修复受损的生态系统以供未来使用，以及更有效地管理生物所需的营养物质。研究人员越来越多地将同步加速器作为工具，以提供对土壤和植物中发生的过程的分子水平的理解，以帮助解决这些复杂的问题。在这项提案中，我们将开发必要的工具，以扩展软X射线光谱，以了解土壤样品中的生命元素（C，N，O，P，S，Ca，Mg，Fe，Cu，Zn）。首先是充分开发一种新的软X射线方法，激发-发射矩阵光谱，以提供宽能量高通量筛选土壤样品。如果成功的话，同步加速器将能够以一种更有意义的方式与生态研究人员进行交流，通过运行统计上显著数量的样本。第二个目标是调查一些新接受的土壤连续模型的影响，土壤有机碳的形式和行为在自然系统中。

Several of the grand challenges facing science today involve being able to better manage Earth's soil resources: Feeding 9 Billion people sustainably via intensification of agriculture, preserving our water resources in the face of a changing climate, effectively restoring and rehabilitating damaged ecosystems for future use, and becoming more efficient at the stewardship of nutrients required for living things. Researchers are increasingly turning to synchrotrons as tools to provide a molecular-level understanding of processes occurring in soils and plants to assist in solving these complex problems. In this proposal, we would develop the necessary tools to extend soft x-ray spectroscopy to understand the elements of life (C, N, O, P, S, Ca, Mg, Fe, Cu, Zn) in soil samples.We have two major objectives in this proposal. The first is to fully develop a novel soft x-ray approach, Excitation-Emission Matrix Spectroscopy, to provide wide energy high throughput screening of soil samples. If successful, then synchrotrons would be able to interface with ecological researchers in a more meaningful way by running statistically significant numbers of samples. The second objective is to investigate some of the implications for the newly accepted soil continuum model for how soil organic carbon forms and behaves in natural systems.