Abstract

Agricultural activities contribute to water pollution through sediments and nutrient export, negatively affecting water quality and aquatic ecosystems. However, implementing best management practices (BMPs) could help control sediments and nutrient losses from agricultural catchments. This study used the Soil Water Assessment Tool (SWAT) model to assess the effectiveness of four BMPs in reducing sediment and phosphorus export in a small agricultural catchment (33 km2) in southeastern Sweden. The SWAT model was first evaluated for its ability to simulate streamflow, sediment load, and total phosphorous load from 2005 to 2020. Then, the calibrated parameters were used to simulate the agricultural BMP scenarios by modifying relevant parameters. The model performed satisfactorily during calibration and validation for streamflow (NSE = 0.80/0.84), sediment load (NSE = 0.67/0.69), and total phosphorous load (NSE = 0.61/0.62), indicating its suitability for this study. The results demonstrate varying effects of BMP implementation on sediment and phosphorus (soluble and total) export, with no significant change in streamflow. Filter strips were highly effective in reducing sediment (-32%), soluble phosphorus (-67%), and total phosphorous (-66%) exports, followed by sedimentation ponds with-35%,-36%, and-50% reductions, respectively. Grassed waterways and no-tillage were less impactful on pollutant reduction, with grassed waterways showing a slight increase (+4%) in soluble phosphorus and no -tillage having a minimal effect on sediment (-1.3%) and total phosphorus (-0.2%) export. These findings contribute to the ongoing efforts to mitigate sediment and nutrient pollution in Swedish agricultural areas, thereby supporting the conservation and restoration of aquatic ecosystems, and enhancing sustainable agricultural practices.

Keywords

BMP implementation; Sediment load; Soluble phosphorous; Total phosphorous; SWAT model

Published in

Agricultural Water Management
2023, Volume: 290, article number: 108595
Publisher: ELSEVIER

SLU Authors

• Oduor, Brian Omondi

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    
  • Public University of Navarre

• Kyllmar, Katarina

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

• Mårtensson, Kristina

  • Department of Soil and Environment, Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG6 Ensure availability and sustainable management of water and sanitation for all


UKÄ Subject classification

Environmental Sciences related to Agriculture and Land-use


Publication identifier

DOI: https://doi.org/10.1016/j.agwat.2023.108595

Permanent link to this page (URI)

https://res.slu.se/id/publ/127626