Irrigation incorporation and tillage impacts on runoff, erosion and preemergence herbicide loss

AGRO 142

Thomas L. Potter, tom.potter@ars.usda.gov1, Timothy C. Strickland, tim.strickland@ars.usda.gov2, Clint C. Truman, clint.truman@ars.usda.gov2, David D. Bosch, david.bosch@ars.usda.gov2, and Ted Webster, ted.webster@ars.usda.gov3. (1) Southeast Watershed Research Laboratory, USDA-ARS, 2316 Rainwater Road, PO Box 748, Tifton, GA 31794, (2) Southeast Watershed Research Laboratory, USDA - Agricultural Research Service, 2316 Rainwater Road, PO Box 748, Tifton, GA 31794, (3) Crop Protection and Management Research Unit, USDA-ARS, P.O. Box 748, Tifton, GA 31794
Post application herbicide incorporation by irrigation has the potential to reduce runoff risks while improving weed control. Although the practice is specified on many product labels environmental benefits are uncertain. To address questions regarding potential impacts in the Coastal Plain region of Georgia (USA), we conducted a series of rainfall simulations and quantified runoff, sediment loss and loss of two herbicides, metolachlor and pendimethalin, as a function of tillage, strip (ST) versus conventional (CT), with and without post-application herbicide incorporation by irrigation. Irrigation contributed to greater runoff volumes (°Ö2X) and increased erosion but loss of both herbicides was reduced in both tillage systems. The impact was greatest for metolachlor on CT plots where a 2-fold reduction was observed. Generally the study demonstrated that irrigation incorporation can reduce preemergence herbicide losses. Adoption and implementation of the practice throughout the region is recommended.
 

New Developments and Issues in Agrochemical Sciences
8:45 AM-11:50 AM, Thursday, August 23, 2007 BCEC -- 259A, Oral

Division of Agrochemicals

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007