SWAT Literature Database for Peer-Reviewed Journal Articles

Title:Management options to reduce phosphorus leaching from vegetated buffer strips 
Authors:Hille, S., D. Graeber, B. Kronvang, G.H. Rubaek, G.H., N. Onnen, E. Molino-Navarro, A. Baattrup-Pedersen, G.J. Heckrath and M.I. Stutter 
Journal:Journal of Environmental Quality 
Volume (Issue):48(2) 
Article ID: 
URL (non-DOI journals): 
Broad Application Category:hydrologic only 
Primary Application Category:evapotranspiration assessment 
Secondary Application Category:none 
Watershed Description:Two research sites located in the southwest part of Jutland in southwest Denmark. 
Calibration Summary: 
Validation Summary: 
General Comments:SWAT was used in just a minor role to provide evapotranspiration estimates for the study. 
Abstract:Vegetated buffer strips (VBS) between agricultural areas and surface waters are important retention areas for eroded particulate P through which they may obtain critically high degrees of P saturation imposing high risk of soluble P leaching. We tested topsoil removal and three harvesting frequencies (once, twice, or four times per year) of natural buffer vegetation to reduce P leaching with the aim to offset erosional P accumulation and high degrees of P saturation. We used a simple numerical time-step model to estimate changes in VBS soil P levels with and without harvest. Harvesting offset erosional deposition as it resulted in an annual ammonium oxalate-extractable P reduction of 0.3 to 2.8% (25-cm topsoil content) in soils of the VBS and thus, with time, reduced potential P leaching below a baseline of 50 mg L−1. Topsoil removal only marginally reduced potential leaching at two sites and not anywhere near this baseline. The harvest frequency only marginally affected the annual P removal, making single annual harvests the most economical. We estimate 50 to 300 yr to reach the P leaching baseline, due to substantial amounts of P accumulated in the soils. Even in high-erosion-risk situations in our study, harvesting reduced soil P content and the P leaching risk. We suggest harvesting as a practical and efficient management to combat P leaching from agricultural VBS, not just for short-term reductions of dissolved P, but also for reductions of the total soil P pool and for possible multiple benefits for VBS.