Diazinon reduction and partitioning between water,sediment and vegetation in stormwater runoff mitigation through rice fields |
| |
Authors: | Matthew T Moore Robert Kröger Charles M Cooper Robert F Cullum Sammie Smith Jr Martin A Locke |
| |
Institution: | 1. Water Quality and Ecology Research Unit, USDA Agricultural Research Service National Sedimentation Laboratory, PO Box 1157, Oxford, MS 38655, USA;2. Department of Wildlife and Fisheries, Mississippi State University, PO Box 9690, Mississippi State, MS 39762, USA |
| |
Abstract: | BACKGROUND: Contamination of surface waters by pesticides is a concern in the United States and around the world. Innovative mitigation strategies are needed to remediate this potential environmental contaminant. One potential solution is to divert pesticide‐laden drainage or surface water through agricultural rice fields. With a hydroperiod, hydrosoil and hydrophyte (rice), these systems serve essentially as a type of constructed wetland. In both summer and fall experiments, diazinon‐amended water was diverted through two rice ponds at the University of Mississippi Field Station. Likewise, a non‐vegetated control pond was amended with diazinon‐laden water. Water, sediment and plant samples were taken spatially and temporally to determine the distribution of diazinon within systems. RESULTS: Outflow diazinon concentrations decreased significantly (P < 0.05) from inflow in both vegetated ponds for both preharvest and post‐harvest experiments. Although sorption to rice plants was minimal in the overall mass distribution of diazinon (1–3%), temporal data indicated that diazinon concentrations reached the outflow sediment of the non‐vegetated control twice as fast as in either vegetated (rice) system. In both vegetated systems, sediment diazinon concentrations decreased (77 and 100%) from inflow to outflow, while a decrease of <2% was noted in the non‐vegetated control. CONCLUSIONS: Diversion of pesticide‐contaminated water through rice fields demonstrated potential as a low‐cost, environmentally efficient mitigation practice. Studies on these systems are continuing to evaluate the optimal chemical retention time for rice field mitigation, as well as diazinon transfer to rice grain seeds that may be used as a food source. Published in 2009 by John Wiley & Sons, Ltd. |
| |
Keywords: | pesticide BMP wetland vegetation |
|
|