Location: Delta Water Management Research
Title: Residual herbicide concentrations in on-farm water storage-tailwater recovery systems: preliminary assessmentAuthor
GRANTZ, ERIN - University Of Arkansas | |
LESLIE, DEBORAH - University Of Memphis | |
Reba, Michele | |
WILLETT, CAMMY - University Of Arkansas |
Submitted to: Agricultural & Environmental Letters
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 2/19/2020 Publication Date: 4/1/2020 Publication URL: https://handle.nal.usda.gov/10113/7019842 Citation: Grantz, E.M., Leslie, D., Reba, M.L., Willett, C. 2020. Residual herbicide concentrations in on-farm water storage-tailwater recovery systems: preliminary assessment. Agricultural and Environmental Letters. https://doi.org/10.1002/ael2.20009. DOI: https://doi.org/10.1002/ael2.20009 Interpretive Summary: On-farm water storage-tailwater recovery systems reduce groundwater usage and intercept agrochemical loads, but pesticide residue dynamics in these systems are less understood. This study monitored concentrations of seven herbicides in seven Northeast Arkansas tailwater recovery systems from April 2017 to March 2018. Clomazone, glyphosate, metolachlor, and quinclorac were frequently detected, with minimal detections of 2,4-D, dicamba, and propanil. Detected concentrations peaked during the growing season (April 1-September 15), reflecting an interaction of application and precipitation. Off-season herbicide concentrations were low and mostly below detection. These findings inform both water managers on potential issues with surface water recycling and those interested in using surface water for managed aquifer recharge. Technical Abstract: On-farm water storage-tailwater recovery systems reduce groundwater usage and intercept agrochemical loads, but pesticide residue dynamics in these systems are less understood. This study monitored concentrations of seven herbicides in seven Northeast Arkansas tailwater recovery systems from April 2017 to March 2018. Clomazone, glyphosate, metolachlor, and quinclorac were frequently detected, with minimal detections of 2,4-D, dicamba, and propanil. Detected concentrations peaked during the growing season (April 1-September 15), reflecting an interaction of application and precipitation. Clomazone, glyphosate, and quinclorac concentrations were higher in ditches than in the associated reservoir, but metolachlor concentrations were similar between structure types. Off-season herbicide concentrations were low and mostly below detection. Cycling recovered tailwater through the system and sourcing irrigation from reservoirs will minimize risk of sensitive crop exposure to residual herbicides. Managed groundwater recharge should use water from reservoirs during winter to protect groundwater quality. |