Peatland as a natural sink for pesticides from no-till systems in subtropical climate

Diffuse pollution of agricultural areas has seriously compromised the quality of water resources. Around the world, peatlands are environments located on the slope lower third, which receive all the runoff and pollutants carried by agricultural areas. We evaluate the behavior of pesticides in peatlands as a natural tool to reduction nonpoint pollution from no-till system. This study was conducted in two steps in a peatland (6 ha) subdivided into three transects. The first step, it was performed a pesticides monitoring from agricultural areas (no-till system). On second step, the pesticide lambda cyhalothrin was applied on experimental plots. The water sampling was performed with the aid of monitoring wells (0-30, 30-60 and 60-90 cm depth), and the removed made with a vacuum pump. Soil sampling was performed introduced PVC pipe diameter of 50 mm at the same depth that water samples. To the first step, the results were as follow: To soil sample, a total of 52 detections were obtained, which are shown in order of relevance for atrazine (32%) chlorpyrifos (27%) lambda-cyhalothrin (19%), fluazifop-p-butyl (11.5%) and lactofen (9%). As for the water samples, 32 results (detections) were performing, atrazine (37%) chlorpyrifos (32%) lambda-cyhalothrin (12.5%) and the fluazifop-p-butyl pesticides (9%) and lactofen (9%) of equal importance. Spatially transect 1 was significantly different from transect 3 for all pesticides studied. The second step showed a significant reduction in the concentration of the pesticide lambda cyhalothrin over time and increasing soil depth. The highest concentration in the samples was at a depth of 0-30 cm, where the organic carbon content was higher. (C) 2015 Elsevier B.V. All rights reserved.