RII Track-4: Microscale processes controlling speciation and transformation of phosphorus in soils

非技术性描述磷（P）在经常相互竞争的食品需求和水质保障中发挥着关键作用。切萨皮克湾是美国的国宝，也是美国第一个被国会列为修复目标的河口。 更好地了解的组成和量的P在分水岭导致海湾将提高我们的能力来预测潜在的风险运动的P从森林，农业和城市来源的海湾沃茨。该项目的科学发现将有助于切萨皮克湾计划、美国地质调查局和美国环境保护局在海湾恢复计划中进行的数十年工作。PI和一名来自特拉华州大学（UD）的研究生将与加州理工学院的科学家合作，使用一套复杂的仪器来确定土壤和沃茨中磷的具体形式和浓度。这项工作将大大提高目前的理解复杂的过程，管理环境命运的P在切萨皮克湾流域，并将使PI能够采用在本地机构中不可用的技术。技术描述多土壤和沃茨中磷的形态和过程在空间和时间尺度上存在差异，因此需要一个先进和创新的分析方法工具箱，提供磷的结构信息，这可以连接的结构，化学反应和转化途径。本研究旨在探讨不同磷库在土壤中的形成、转化及其向开放沃茨迁移的机制。它将利用先进的分析技术，包括空间分辨电子微探针分析、二次离子质谱（纳米二次离子质谱和磁性西姆斯）和激光烧蚀同位素质谱仪。此外，在轻同位素系统学的一系列理论和实验的发展将被应用到识别和解释微观尺度磷形态，物理化学协会和原位分布的磷酸盐氧同位素和它们的相互关系，在短期和长期的土壤培养以及在土壤时序研究。该奖学金将最大限度地提高PI在几种新型同位素技术方面的研究生产力和领导力，所获得的知识和经验将在未来催化新的研究前沿。该项目的调查结果将提供给UD合作推广和其他州和地方机构，以共同努力，最大限度地减少农业土壤中养分的损失，并帮助实现减少污染物的目标。

Non-technical DescriptionPhosphorus (P) plays a pivotal role in the often-competing demands of food and safeguarding water quality. Chesapeake Bay is a national treasure and the nation's first estuary targeted by Congress for restoration. Improved understanding of the composition and the amount of P in the watershed leading to the Bay will enhance our ability to predict the potential risk of movement of P from forest, agricultural, and urban sources to the Bay waters. Scientific findings from this project will contribute to decades of work conducted by the Chesapeake Bay Program, US Geological Survey, and US Environmental Protection Agency in the Bay restoration plan. The PI and a graduate student from the University of Delaware (UD) will work with scientists at the California Institute of Technology to use a suite of sophisticated instrumentation that will determine the specific forms and concentrations of P in soils and waters. This work will greatly improve the current understanding of the complex processes that govern the environmental fate of P in the Chesapeake Bay watershed, and will enable the PI to employ techniques that are not available at the home institution.Technical DescriptionMulti-scale interactions among forms of P and processes in soils and waters that vary across spatial and temporal scales call for a toolbox of advanced and innovative analytical methods capable of providing P structural information, which can connect the structure to chemical reactivity and transformation pathways. This research aims to identify the mechanisms of formation and transformation of different P pools in soils and its transport to open waters. It will utilize advanced analytical techniques, including spatially resolved electron microprobe analysis (EMPA), secondary ion mass spectrometry (nanoSIMS and magnetic SIMS), and laser ablation isotope mass spectrometer (LA-IRMS). In addition, a series of theoretical and experimental developments in light isotope systematics will be applied to identify and interpret microscale P speciation, physico-chemical association and in situ distribution of phosphate oxygen isotopes and their interrelationship in short- and long-term soil incubation as well as in soil chronosequence studies. This fellowship will maximize the PI's research productivity and leadership in several novel isotope techniques, and the knowledge and experience gained will catalyze new research fronts in the future. Findings from the project will be provided to the UD Cooperative Extension and other state and local agencies for their collective efforts to minimize the loss of nutrients from agricultural soils and to help achieve pollutant reduction goals.