ARS | Publication request: USE OF GRASS BUFFERS TO MITIGATE HERBICIDE LOSS IN RUNOFF UNDER SIMULATED RAINFALL CONDITIONS [ABSTRACT]

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: October 6, 2004
Publication Date: February 8, 2005
Citation: Locke, M. A., Zablotowicz, R. M., Steinriede Jr, R. W., Reddy, K. N. 2005. Use of grass buffers to mitigate herbicide loss in runoff under simulated rainfall conditions [abstract]. Weed Science Society of America Meeting Abstracts. 45:329.

Technical Abstract: Studies were conducted to determine benefits of bahia grass (Paspalum notatum) buffer strip in mitigating atrazine and fluometuron loss in runoff from erosion trays under simulated rainfall. Two separate experiments were conducted, first with fluometuron, then with atrazine. Except for herbicide treatment, all procedures were the same for both experiments. Fluometuron (1.68 kg ai ha-1) and atrazine (2.24 kg ai ha-1) were applied to the surface of runoff trays (2.73 m2 area, 1.2% slope) containing Dundee silt loam soil. Herbicide was applied to only the upslope half of each tray 24 h before rainfall simulation. Treatments included either bare soil or a 1-m bahia grass strip at the downslope outlet end of the tray and were replicated four times. Simulated rainfall was applied to the upslope half of each tray (2.5 cm in 20 min; Vee-Jet oscillating nozzles). Runoff was collected in fractions and processed for sediment and herbicide concentrations (by ELISA). Soil was collected after rainfall simulation and analyzed for herbicide concentration by HPLC. Water runoff from bare trays was almost twice as much as the grass buffer treatments (205 L vs. 105 L), with average sediment loss of 21.6 kg (s.e. 4.7) per bare tray versus 1.16 kg (s.e. 0.27) per grass buffer tray. Total fluometuron loss in runoff from bare soil treatments was 11.6% (s.e. 2.5) vs. 2.6% (s.e. 0.1) from grass buffer treatments. Similarly, atrazine loss from bare vs. grass buffer treatments was 15.8% (s.e. 1.7) and 5.0% (s.e. 0.9), respectively. Results demonstrated the utility of including grass buffers at the edge of fields as an impediment for water, sediment, and herbicide loss.