Journal article
Simulation of targeted pollutant-mitigation-strategies to reduce nitrate and sediment hotspots in agricultural watershed
Science of the Total Environment, Vol.607-608, pp.1188-1200
12/31/2017
DOI: 10.1016/j.scitotenv.2017.07.048
PMID: 28732398
Abstract
About 50% of U.S. water pollution problems are caused by non-point source (NPS) pollution, primarily sediment and nutrients from agricultural areas, despite the widespread implementation of agricultural Best Management Practices (BMPs). However, the effectiveness of implementation strategies and type of BMPs at watershed scale are still not well understood. In this study, the Soil and Water Assessment Tool (SWAT) ecohydrological model was used to assess the effectiveness of pollutant mitigation strategies in the Raccoon River watershed (RRW) in west-central Iowa, USA. We analyzed fourteen management scenarios based on systematic combinations of five strategies: fertilizer/manure management, changing row-crop land to perennial grass, vegetative filter strips, cover crops and shallower tile drainage systems, specifically aimed at reducing nitrate and total suspended sediment yields from hotspot areas in the RRW. Moreover, we assessed implications of climate change on management practices, and the impacts of management practices on water availability, row crop yield, and total agricultural production. Our results indicate that sufficient reduction of nitrate load may require either implementation of multiple management practices (38.5% with current setup) or conversion of extensive areas into perennial grass (up to 49.7%) to meet and maintain the drinking water standard. However, climate change may undermine the effectiveness of management practices, especially late in the 21st century, cutting the reduction by up to 65% for nitrate and more for sediment loads. Further, though our approach is targeted, it resulted in a slight decrease (~5%) in watershed average crop yield and hence an overall reduction in total crop production, mainly due to the conversion of row-crop lands to perennial grass. Such yield reductions could be quite spatially heterogeneously distributed (0 to 40%). [Display omitted] •Spatially unique hydrologic response units (HRUs) help identify pollutant hotspots.•Simulation of management practices on targeted hotspots is more explicit.•Sufficient reduction of nitrate load requires extensive management practices.•The effectiveness of management practices will be undermined by climate change.•Optimization could help reduce potential impacts of practice on crop yield.
Details
- Title: Subtitle
- Simulation of targeted pollutant-mitigation-strategies to reduce nitrate and sediment hotspots in agricultural watershed
- Creators
- Awoke Dagnew Teshager - Graham Sustainability Institute, University of Michigan, Ann Arbor, MI 48104, United StatesPhilip W Gassman - Iowa State University, Center for Agricultural and Rural Development, Department of Economics, Ames, IA 50011, United StatesSilvia Secchi - Southern Illinois University Carbondale, Geography and Environmental Resources, Faner Hall, Carbondale, IL 62901, United StatesJustin T Schoof - Southern Illinois University Carbondale, Geography and Environmental Resources, Faner Hall, Carbondale, IL 62901, United States
- Resource Type
- Journal article
- Publication Details
- Science of the Total Environment, Vol.607-608, pp.1188-1200
- Publisher
- Elsevier B.V
- DOI
- 10.1016/j.scitotenv.2017.07.048
- PMID
- 28732398
- ISSN
- 0048-9697
- eISSN
- 1879-1026
- Grant note
- DOI: 10.13039/100000199, name: U.S. Department of Agriculture; DOI: 10.13039/100005825, name: National Institute of Food and Agriculture, award: 20116800230190; DOI: 10.13039/100000001, name: National Science Foundation, award: 100925
- Language
- English
- Date published
- 12/31/2017
- Academic Unit
- Public Policy Center (Archive); Geographical and Sustainability Sciences; University College Courses
- Record Identifier
- 9983917692802771
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