Critical Source Area Index Use for Agricultural Runoff Management скачать в хорошем качестве

Critical Source Area Index Use for Agricultural Runoff Management

Patrick Drohan, Ecosystem Service and Management, Penn State University 2021 NCSS National Conference Advising farm operators how to reduce phosphorus (P) runoff from non-point source agricultural fields is typically done in the central Appalachians USA using a combination of farm visits, conservation plan development and P-Index application. However, recent research in Europe has shown that the identification of areas of high runoff mobilization potential (hydrologically sensitive areas (HSA)) that coincide with a P sources (a critical source areas (CSA)) can better identify site-specific areas of risk of P transfer to surface waters. We developed a CSA Index model for four case study sub-watersheds within the Mahantango watershed using: LiDAR to model sub-field topography; SSURGO data; agronomic based soil test P levels; and field geophysics to identify restrictive layers. The CSA index was developed using agronomic (within field boundary) Mehlich-3 soil test P analysis at 5 and 15 cm and evaluated using high-resolution within field environmental testing (within CSA). Results suggest that both approaches to CSA Index development produce similar site-specific field data. Environmental testing more specifically identifies areas to target for management and can give farmers site-specific information on how their behavior change can improve water quality. Most importantly, the application of a CSA index shows that traditional riparian buffer designs being used may in some cases be inadequate to capture current runoff and in many other cases over-designed. USDA is an equal opportunity provider, employer, and lender.