Protecting Puget Sound watersheds from agricultural pollution using a progressive manure application risk management (ARM) system

Throughout the Puget Sound region, impacted and poorly managed agriculture has been repeatedly advanced as a leading contributor to surface and ground water pollution, particularly during the winter months. A study conducted from 2010 - 2015 aimed to develop an Application Risk Management (ARM) System to minimize pollution from manure in Whatcom County. 


Impacted and poorly managed agriculture has been advanced as a leading contributor to surface and ground water pollution. Improvements in manure application methods and tools are necessary to further protect resources. This study developed an innovative Application Risk Management (ARM) System targeting the transport of manure pathogens and nutrients (N, P) via runoff and leaching by using validated real-time assessment tools. The study was conducted on dairy forage fields from 2010-15 in Whatcom County, WA. A vigorous sampling campaign was conducted on 6 plots comparing conventional manure application strategies to strategic application using a real-time ARM system developed by this project. Soil water was sampled at storm events using 6 gravitational lysimeters placed at 12, 24 and 36 in below the soil surface at random locations within each plot. Soil samples were taken 1-2 times monthly at same depths and locations. In addition, surface water was sampled in-stream at storm events; manure was sampled at each application; forage was sampled at each cutting; and meteorological and management parameters were collected daily. Data was used to create and proof a web-based, easy to use worksheet that farmers use to evaluate manure application runoff risk on a specific field and day using real-time forecast, soil and field parameters. A Manure Spreading Advisory (MSA) was developed to provide a three day risk rating map for runoff based on precipitation forecast. Support tools included a website, dynamic manure application setback distances, and field level risk mapping. The ARM system provided flexibility and accountability to farmers for maximizing crop production and protecting water quality.

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