Vegetative buffer strips show limited effectiveness for reducing antibiotic transport in surface runoff

Authors: MOODY, ADAM - University Of Missouri; LERCH, ROBERT - Retired ARS Employee; GOYNE, KEITH - Virginia Polytechnic Institution & State University; ANDERSON, STEPHEN - University Of Missouri; MENDOZA-COZATL, DAVID - University Of Missouri; ALVAREZ, DAVID - Us Geological Survey

Submitted to: Journal of Environmental Quality
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/15/2022
Publication Date: 12/23/2022
Citation: Moody, A.H., Lerch, R.N., Goyne, K.W., Anderson, S.H., Mendoza-Cozatl, D.G., Alvarez, D.A. 2022. Vegetative buffer strips show limited effectiveness for reducing antibiotic transport in surface runoff. Journal of Environmental Quality. 52(1):137-148. https://doi.org/10.1002/jeq2.20441.
DOI: https://doi.org/10.1002/jeq2.20441

Interpretive Summary: Land application of livestock manure can introduce veterinary antibiotics (VAs) into the soil environment where they may be transported to streams and lakes by surface runoff. Vegetative buffer strips (VBS) have been demonstrated to effectively reduce the amounts of sediment, nutrients, and herbicides in surface runoff, but their effectiveness for reducing VAs in runoff has not been well documented. Therefore, the objective of this study was to determine the effectiveness of different types and widths of grass buffers in reducing the amount of two VAs, sulfamethazine (SMZ) and lincomycin (LIN), in surface runoff. Turkey litter containing the VAs was applied to field plots, a rainfall simulator was used to create runoff, and the runoff was collected and analyzed for SMZ and LIN. Under the conditions studied, VBS had only a limited ability to reduce SMZ and LIN in runoff, with expected field-scale reductions of 16% or less for all buffer treatments. Overall, the grass VBS tested here were less effective at reducing SMZ and LIN in surface runoff than has been previously reported for sediment, nutrients, and herbicides. This study provides important information for landowners and scientists by emphasizing the need to develop and implement management strategies other than VBS to mitigate VA contamination of surface water.

Technical Abstract: Vegetative buffer strips (VBS) have been demonstrated to effectively reduce loads of sediment, nutrients, and herbicides in surface runoff, but their effectiveness for reducing veterinary antibiotic (VA) loads in runoff has not been well documented. The objective of this study was to determine the effectiveness of VBS vegetation and width on surface runoff loads of the VAs sulfamethazine (SMZ) and lincomycin (LIN). Experimental design of the plots (1.5 X 25 m) was a two-way factorial with four vegetation treatments (tall fescue; tall fescue with switchgrass hedge; warm-season native grass mix; and continuous fallow control), and four buffer widths (0, 2, 5, and 9 m). Turkey litter spiked with SMZ and LIN was applied to the source area (upper 7 m) of each plot and runoff was collected at each width. Runoff was generated with a rotating boom simulator. Results showed VA loads in runoff at the 0 m sampler ranged from 3.8 to 5.9% of applied, and overall VA transport in runoff was predominately in the dissolved-phase (90% for SMZ and 99% for LIN). Among vegetation treatments, only tall fescue significantly reduced loads of SMZ and LIN compared to the control, with load reductions of ~30% for both VAs. Estimated field-scale reductions in VA loads showed that source-to-buffer area ratios (SBARs) of 10:1 to 20:1 reduced VA loads by only 7 to 16%. Overall, the grass VBS tested here were less effective at reducing SMZ and LIN loads in surface runoff than has been previously demonstrated for sediment, nutrients, and herbicides.