Reducing atrazine leaching by integrating reduced herbicide use with mechanical weeding in corn (Zea mays)

Concern about the effects of pesticides on the environment and the desire t o reduce purchased inputs are stimuli to reduce herbicide use. Field resear ch was conducted for three growing seasons to compare the chemical contamin ation and effectiveness of three weed management practices. Weed control tr eatments included application of a herbicide mixture of 1.5 kg ai ha(-1) of atrazine plus 0.9 kg ai ha(-1) of pyridate, this mixture being broadcast a lone or band-applied in combination with mechanical weeding, and mechanical weeding alone. The results show that it is possible to decrease the amount of atrazine residue in soil with the band-applied treatment. Such a method is very attractive because crop yields were not decreased, at least in the short run. However, we do not yet know the long-term efficiency of this me thod regarding groundwater quality, weed population dynamic and crop yield. Further work is therefore needed to assess the long-term impact of this we eding method. (C) 1999 Elsevier Science B.V. All rights reserved.