Submitted to: Transactions of the ASABE
Publication Type: Abstract Only
Publication Acceptance Date: November 1, 2001
Publication Date: November 5, 2001
Citation: Vellidis, G., Lowrance, R.R., Wauchope, R.D. 2001. Herbicide movement in a restored riparian forest wetland. Transactions of the ASAEB 45(1):89-97. Technical Abstract: Few studies exist on the movement of pesticides through riparian buffer systems (RBS). Herbicides (atrazine and alachlor) and bromide (as a conservative tracer) were applied above a restored RBS in the Georgia Coastal Plain. The RBS was restored based on USDA guidelines for a three zone buffer system: Zone 1- permanent woody vegetation (hardwoods) along the stream; Zone 2 - managed forest (pines) upslope from Zone 1; and Zone 3- grass buffer upslope from Zone 2. The site was a first-order channel in a wetland pasture where the riparian forest was logged in 1985. The RBS was re-established in 1991 and the herbicides were applied upslope from the buffer in 1993 and 1994. Herbicide and bromide concentrations were determined with a series of wells and surface runoff collectors within the restored buffer below the herbicide application area. Concentrations of atrazine and alachlor in shallow groundwater were consistently and significantly reduced in the RBS. Atrazine concentrations were reduced more than the bromide concentration but alachlor was not. Herbicide concentrations in surface runoff were reduced as water moved through the RBS. The largest decreases took place in the grass buffer, especially for atrazine. Alachlor concentrations were reduced further in the forest buffer. Most of the herbicide load reduction occurred in the grassed Zone 3.