Leaching of 2,4-d and atrazine herbicides in red-yellow latosol

Abstract

The intensive use of herbicides has increased the possibility of environmental contamination and the accumulation of pesticide residues in soil and water. This work aimed to evaluate the leaching potential of 2,4-D and atrazine herbicides in red yellow Latosol with a clayey texture. The experimental design was entirely randomized, in factorial 5x3 (five doses of each herbicide for three soil depths). The doses used were 1.25, 2.50, 6.25 and 12.50 L ha-1 for the 2.4-D herbicide and 2.25, 4.50, 11.25 and 22.50 L ha-1 for the atrazine herbicide (plus absolute witnesses). The herbicides were applied in buried pvc tubes to the soil and after accumulated rainfall of 87 mm, cucumber was grown as a bio indicator plant. The plant phytotoxicity, plant height, dry mass accumulation and leaf area where the evaluations were performed at 21 days after the sowing of the cucumber were analyzed. The 2.4-D herbicide didn`t present significant difference between treatments for the plant phytotoxicity variable, however, there was difference between treatments for plant height and dry mass. For leaf area, the difference was observed only for soil depths. Atrazine herbicide also showed no difference between treatments for plant phytotoxicity, but there was a difference between treatments and soil depths for the other variables. Under the conditions evaluated, 2,4-D and atrazine herbicides can leach into clayey soil regardless of the dose used and can reach up to 30 cm depth.

Keywords

• depth, doses, cucumber, soil