RII Track-4: Elucidating controls of sediment phosphorus delivery to tile-drains

RII Track-4：阐明沉积物磷向瓷砖排水沟输送的控制

• 批准号: 2032701
• 负责人: William Ford
• 金额: $ 22.68万
• 依托单位: University of Kentucky Research Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2032701&HistoricalAwards=false
• 关键词: RII; Track; Elucidating; controls; sediment

Subsurface tile-drainage is widely used to increase crop yields in poorly drained, agricultural landscapes across the nation. Sediment-bound phosphorus (P) loadings from tile-drainage are contributing to the excessive richness of nutrients in a body of water, through water run-off, and increasing the prominence of harmful algae in downstream waterbodies. There are major gaps in understanding of sediment erosion and transport dynamics through tile-drains, which has limited our ability to manage these contaminants from agricultural fields. This research will provide funding for a tenure-track Assistant Professor, and a graduate research assistant from the University of Kentucky to conduct extended site visits at the National Soil Erosion Research Laboratory (NSERL) in West Lafayette, Indiana. The PI and his student will collaborate with researchers at NSERL to perform laboratory rainfall simulations to study mechanisms of sediment erosion and transport through subsurface soils. The research team will also enhance computer simulation tools that can capture tile sediment P loadings from fields in order to improve management strategies. Tile-drainage is increasingly implemented in the PI’s state of Kentucky, as well as food-production systems across the country. This research will improve infrastructure for researching and managing tile-drainage water quality, advance graduate curricula at the PI’s home institution, and provide training for an underrepresented student in STEM. Recent studies have highlighted the importance of dissolved reactive phosphorus (DRP) that is regenerated from streambed sediments as a major source of watershed-scale DRP loading. There is now renewed interest in quantifying and managing sediment-bound particulate P (PP) delivered through tile-drains. Mechanisms controlling sediment erosion and transport dynamics in macropores are not well understood, particularly the impact of biological crust development on macropore walls and how it influences flow pathway dynamics and sediment erodibility. Further, field-scale controls on PP delivery to tile drains have been hypothesized, but not quantified, which stems from a lack of field datasets and limited representation of subsurface PP delivery through tile drains in agricultural water management models. The research team will collaborate with the National Soil Erosion Research Laboratory (NSERL) to study the impact of macropore biological crust development on sediment erosion and flow pathway dynamics. Fellowship activities include the use of rainfall experiments on undisturbed soil lysimeters with a growth and control condition. The team will also modify the Water Erosion Prediction Project (WEPP) model to include subsurface flow pathways and sediment P erosion and transport routines for tile drainage, which will be evaluated at both field and watershed scales using long-term datasets managed by NSERL. The infrastructure developed in this proposal may be used to inform weighting factors and model structure for empirically-based tools used by practitioners, such as P-indices. The proposed research activities will improve mechanistic understanding of subsurface erosion processes, advance numerical modeling infrastructure at field-watershed scales for subsurface drained agroecosystems, and will quantify the prominent mechanisms causing PP transport to tile drains.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地下瓦排水广泛用于提高全国排水不良的农业景观中的农作物产量，瓦排水中沉积物中的磷 (P) 负荷通过水流导致水体中营养物质过度丰富。 -关闭，并增加了下游水体中有害藻类的重要性。对沉积物侵蚀和通过瓷砖排水沟的运输动态的了解存在重大差距，这限制了我们管理这些污染物的能力。这项研究将为肯塔基大学的终身教授和研究生研究助理提供资金，以在印第安纳州西拉斐特的国家土壤侵蚀研究实验室 (NSERL) 进行长期实地考察。他的学生将与 NSERL 的研究人员合作进行实验室降雨模拟，以研究沉积物侵蚀和地下土壤输送的机制。该研究团队还将增强计算机模拟工具，以捕获田间沉积物的磷负荷，以改进管理策略。 。瓷砖排水在 PI 所在的肯塔基州以及全国各地的粮食生产系统中得到越来越多的应用。这项研究将改善研究和管理瓷砖排水水质的基础设施，推进 PI 所在机构的课程并提供培训。最近的研究强调了从河床沉积物中再生的溶解活性磷 (DRP) 作为流域规模 DRP 负荷的主要来源的重要性。现在人们对通过瓷砖排水沟输送的沉积物结合颗粒磷（PP）重新产生了兴趣。控制沉积物侵蚀和大孔隙中传输动力学的机制尚不清楚，特别是生物结皮发育对管理大孔隙壁的影响及其如何影响。此外，已经捕获了对 PP 输送到瓷砖排水沟的现场规模控制，但尚未量化，这是由于缺乏现场数据集和地下 PP 输送的代表性有限。该研究小组将与国家土壤侵蚀研究实验室（NSERL）合作，研究大孔生物结皮发育对沉积物侵蚀和水流路径动力学的影响，包括在未受干扰的情况下进行降雨实验。该团队还将修改水侵蚀预测项目（WEPP）模型，以包括地下流动路径和沉积物 P 侵蚀以及瓷砖排水的运输程序，这将在两个方面进行评估。使用 NSERL 管理的长期数据集来评估田野和流域尺度，该提案中开发的基础设施可用于为从业者使用的基于经验的工具（例如 P 指数）提供权重因子和模型结构。对地下侵蚀过程的机械理解，在田间流域尺度上推进地下排水农业生态系统的数值模拟基础设施，并将量化导致 PP 传输到瓷砖排水沟的重要机制。该奖项反映了 NSF 的法定使命和通过使用基金会的智力价值和更广泛的影响审查标准进行评估，该项目被认为值得支持。