Runoff generation and phosphorus mobilization in agricultural landscapes

以农业为主的集水区的非点源磷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，在大型湖泊中观察到有害藻华（HABs）的频率越来越高。尽管实施了有益管理措施（BMPs）来减少磷的损失，但在某些地区，磷负荷并没有减少，实际上还在增加。现有的磷输出模型和管理策略主要针对降雨事件驱动的地表径流，而不能有效地解决冬季过程和融雪期。这一时期代表了我们对农业地区磷动员的科学认识的重大差距。在全球许多中纬度地区，冬季是径流和磷的主要年通量，因此有必要了解冬季和早春磷损失的驱动因素。

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 Algal Blooms (HABs) have been observed in large lakes with increasing frequency. Despite the implementation of Beneficial Management Practices (BMPs) to reduce P loss, P loads are not decreasing and in fact are increasing in some regions. Existing models for P export and management strategies largely target rainfall event-driven surface runoff and do not effectively address winter processes and the snowmelt period. This period represents a significant gap in our scientific understanding of P mobilization in agricultural regions. In many midlatitude regions globally, the winter period is the dominant annual flux for both runoff and P. Thus, an understanding of the drivers of P loss in winter and early spring is needed.