INFLUENCE OF DRAINPIPE SPACINGS ON ATRAZINE LEACHING

Maize (Zea mays) is the leading culture according to sow area in Croatia. Herbicide products based on atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine) are most widely used for weed control in corn crops. Therefore the aim of this study was to determine the concentration and leaching of atrazine in drainage water in four different variants of pipe drainage spacing (15 m, 20 m, 25 m and 30 m). The study was conduced on the Jelenscak reclamation test field, on hydroameliorated Gleyic Podzoluvisol during four years. Atrazine extracted from the samples of drainage waters was determinated by gas chromatography. Data were statistically processed by means of analysis of variance. The concentrations of the atrazine recorded in drainage waters varied in a wide range, with maximum values recorded soon after its application and at the start of higher drainage discharge. The results indicate that maximal and average concentrations of atrazine in drainage waters exceeded the maximum allowable concentration (MAC) for single herbicides in drinking water (0,1 μg l-1), respectively, in the larger part of the year in all variants of pipe drainage spacing. There were no statistically significant differences between the tested drainage systems in drainage water contamination with atrazine.