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Using the Soil and Water Assessment Tool to Estimate Achievable Water Quality Targets through Implementation of Beneficial Management Practices in an Agricultural Watershed
Author(s) -
Yang Qi,
Benoy Glenn A.,
Chow Thien Lien,
Daigle JeanLouis,
Bourque Charles P.A.,
Meng FanRui
Publication year - 2012
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2010.0250
Subject(s) - water quality , watershed , agriculture , environmental science , water resource management , soil and water assessment tool , agricultural management , watershed management , quality (philosophy) , agricultural engineering , environmental resource management , hydrology (agriculture) , environmental planning , computer science , engineering , geography , ecology , drainage basin , cartography , geotechnical engineering , machine learning , streamflow , biology , philosophy , archaeology , epistemology
Runoff from crop production in agricultural watersheds can cause widespread soil loss and degradation of surface water quality. Beneficial management practices (BMPs) for soil conservation are often implemented as remedial measures because BMPs can reduce soil erosion and improve water quality. However, the efficacy of BMPs may be unknown because it can be affected by many factors, such as farming practices, land‐use, soil type, topography, and climatic conditions. As such, it is difficult to estimate the impacts of BMPs on water quality through field experiments alone. In this research, the Soil and Water Assessment Tool was used to estimate achievable performance targets of water quality indicators (sediment and soluble P loadings) after implementation of combinations of selected BMPs in the Black Brook Watershed in northwestern New Brunswick, Canada. Four commonly used BMPs (flow diversion terraces [FDTs], fertilizer reductions, tillage methods, and crop rotations), were considered individually and in different combinations. At the watershed level, the best achievable sediment loading was 1.9 t ha −1 yr −1 (89% reduction compared with default scenario), with a BMP combination of crop rotation, FDT, and no‐till. The best achievable soluble P loading was 0.5 kg ha −1 yr −1 (62% reduction), with a BMP combination of crop rotation and FDT and fertilizer reduction. Targets estimated through nonpoint source water quality modeling can be used to evaluate BMP implementation initiatives and provide milestones for the rehabilitation of streams and rivers in agricultural regions.