Phosphorus mobilization in artificially drained agricultural landscapes

人工排水农业景观中的磷动员

• 批准号: RGPIN-2022-02952
• 负责人: Macrae, Merrin
• 金额: $ 3.72万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=754889
• 关键词: Phosphorus; mobilization; artificially; drained; agricultural

Phosphorus (P) export from non-point sources in agriculture-dominated catchments is a global issue, and a priority area for many regions in Canada, where harmful and nuisance algal blooms have been observed in lakes with increasing frequency. Despite the implementation of conservation practices to reduce P loss, P loads are not decreasing and are increasing in some regions. Some of the accelerated losses of P have been linked to the artificial (tile) drainage of agricultural lands, which can rapidly deliver nutrients from recently applied fertilizers as well as legacy stores in the landscape. With the anticipated intensification of the hydrological cycle under a changing climate, tile drainage is expanding throughout North America. Our current conceptual understanding of P mobilization in tile drainage is overgeneralized across different landscapes, climates and management scenarios. Thus, a clearer understanding of the risks of nutrient loss associated with tile drainage is needed. The goal of this proposal, and the short-term objective of my research program is to improve scientific understanding of the impacts of tile drainage on P supply and transport processes from agricultural landscapes. Over the next five years, my research team will provide an improved understanding of P mobilization through the unsaturated vadose zone into tile drains (tile scale) and an improved understanding of differences in P mobilization in tile drained fields with contrasting hydrology (ie poor internal drainage with little groundwater interaction vs variable source area hydrology with shallow groundwater interaction). The proposed work will characterize the complexities of P dynamics across a range of landscapes and environmental conditions. Field investigations will be coupled with novel experiments, and a minimum of five graduate students will be trained as part of this work. This program will have significant environmental and economic impacts as it addresses issues related to land management (tile drainage) as well as climate (and climate change), which are relevant to agriculture and food security. This research is based on data-driven field observations and includes the winter period, during which there is a weak understanding of processes and a paucity of data, and therefore addresses a significant knowledge gap. This will provide an innovative understanding of the contributions of tile drainage to P losses, which is important to balance both crop yields and water quality and thus ensure to future food and water security.

以农业为主的集水区非点源磷 (P) 出口是一个全球性问题，也是加拿大许多地区的优先领域，在这些地区，湖泊中有害藻类大量繁殖的现象越来越频繁。尽管实施了保护措施来减少磷损失，但磷负荷并没有减少，在一些地区还在增加。磷的加速损失部分与农田的人工（瓷砖）排水有关，这种排水可以迅速从最近施用的肥料以及景观中遗留的储存中输送养分。随着气候变化下水文循环的预期加剧，瓷砖排水系统正在整个北美地区扩大。我们目前对瓷砖排水中磷动员的概念理解在不同的景观、气候和管理方案中过于笼统。因此，需要更清楚地了解与瓷砖排水相关的养分损失风险。该提案的目标以及我的研究计划的短期目标是提高对瓦排水对农业景观磷供应和运输过程影响的科学理解。在接下来的五年中，我的研究团队将更好地了解通过不饱和包气带进入瓦排水沟（瓦片规模）的磷动员，并更好地了解具有对比水文（即内部排水不良）的瓦排水田中磷动员的差异与少量地下水相互作用对比可变源区水文与浅层地下水相互作用）。拟议的工作将描述一系列景观和环境条件下磷动态的复杂性。现场调查将与新颖的实验相结合，作为这项工作的一部分，至少五名研究生将接受培训。该计划将产生重大的环境和经济影响，因为它解决了与土地管理（瓷砖排水）以及气候（和气候变化）相关的问题，这些问题与农业和粮食安全相关。这项研究基于数据驱动的实地观察，包括冬季，在此期间对过程的理解薄弱且数据缺乏，因此解决了重大的知识差距。这将为了解瓦片排水对磷损失的贡献提供一个创新的认识，这对于平衡作物产量和水质，从而确保未来的粮食和水安全非常重要。