ARS | Publication request: Evaluating the Influence of Drainage, Application, and Tillage Practices on the Dissipation of Chloroacetanilide Herbicides in Minnesota Soils

Submitted to: Trade Journal Publication
Publication Type: Proceedings/Symposium
Publication Acceptance Date: August 10, 2008
Publication Date: August 13, 2008
Citation: Rice, P.J., Koskinen, W.C., Papiernik, S.K., Strock, J. 2008. Evaluating the Influence of Drainage, Application, and Tillage Practices on the Dissipation of Chloroacetanilide Herbicides in Minnesota Soils. In: Proceedings of the 3rd Agricultural Drainage Field Day. Soil and Water Management Field Day Proceedings 2008, August 13, 2008, Lamberton, MN. 2008 CDROM.

Technical Abstract: Acetochlor and metolachlor are herbicides used in Minnesota and the United States for the control of broadleaf and annual weeds in corn, soybean and other crops. Water monitoring studies have reported the occurrences of acetochlor, metolachlor and their breakdown products in both ground and surface water, indicating these compounds are prone to leaching and runoff. Detection of pesticides and their breakdown products in water resources has lead to public concern as their presence in surface water can have adverse effects on aquatic organisms and their occurrence in surface and ground water may impact the quality of drinking water supplies. The USDA-Agricultural Research Service, in collaboration with the University of Minnesota, is investigating the persistence and transport of acetochlor and metolachlor under a variety of cropping practices to identify those that reduce the risk of water contamination while maintaining good weed control. Three research projects are in progress to evaluate the following: 1) the potential of drainage water management and herbicide application rates to reduce acetochlor loss from agricultural fields, 2) the dissipation and mobility of metolachlor in row crop soils managed with different tillage practices and 3) the persistence of metolachlor following fall and spring application and its influence on weed control. A greater understanding of the environmental fate of acetochlor and metolachlor will allow for informed decisions and practical application of agricultural management practices that will increase their retention and efficacy at sites of application while reducing herbicide concentrations in surrounding surface or ground waters; thereby minimizing exposure and adverse impacts to non-target organisms and environments.