Submitted to: Water Management to Meet Emerging TMDL Environmental Regulations Conference
Publication Type: Proceedings
Publication Acceptance Date: 10/20/2003
Publication Date: 11/8/2003
Citation: Cullum, R.F., Moore, M.T., Knight, S.S., Rodrigue, P.B. 2003. Pesticide mitigation in drainage ditches and constructed wetlands for agricultural non-point source runoff. Water Management to Meet Emerging TMDL Environmental Regulations Conference. 486-493. Interpretive Summary: Oxbow lakes in the Mississippi Delta have not escaped the detrimental effects of pesticides and soil erosion. A solution to reducing these pesticides and sediments entering the lakes is through trapping them in the drainage ditches common to this area and within the wetlands adjacent to the lakes. This study offers field data that shows the reduction of the pesticide atrazine in both the ditches and wetland based on time and flow length of water. Wetland volumes for pesticide detention and processing were given in paper. Land owners and farmers in the Mississippi Delta will find this information provides results that their drainage ditches when maintained not only convey water from agricultural fields but also reduce pesticides entering lakes. These results also will be useful to extension personnel, action agencies involved in water quality planning, and engineers in constructing wetlands for pesticide mitigation.
Technical Abstract: Atrazine was amended into an agricultural drainage ditch and constructed wetlands for the purpose of monitoring transport and fate of the pesticide. Aqueous half lives of 6 and 16 to 48 days in drainage ditch and constructed wetlands, respectively, were found. Flow paths of 50 m and 103 to 281 m were required to mitigate atrazine in the drainage ditch and constructed wetlands, respectively. This information provided design parameters for ditches and constructed wetlands to mitigate the herbicide in agricultural runoff.