The research object was to investigate the influence of different pipe drainage systems on the concentration and quantity of atrazine leached in drainage water, as well as in surface (0-30 cm) and sub-surface (30-60 cm) soil horizons in the production of agricultural crops on drained Gleyic Podzoluvisol. Investigations involved four different variants of drainpipe spacing (15 m, 20 m, 25 m and 30 m ; i.e. four variants in four repetitions). In a particular trial year, the same crop was grown and the same agricultural practices applied in all trial variants. Maize was grown in the first two trial years and wheat in the last year. Soil and water samples were qualitatively and quantitatively analysed for the presence of atrazine by gas chromatography. Atrazine concentrations in drainage water ranged from those within the limits tolerated for drinking water (out of the growing season) up to 458 ng. dm-3. Maximum quantity of leached atrazine was recorded in 1998 (0.500 g. ha-1), namely, from atrazine application in May 1997 to March 1998 incl., 0.630 g.ha-1 or 0.052% of the initially added quantity was leached. Maximum atrazine concentration in the surface soil layer was recorded in traces or it was not recorded at all (0.013 mg.kg-1), whereas no atrazine was recorded in the subsurface layer during the trial period. Analysis of variance produced no statistically significant difference in the atrazine concentration and leaching in drainage water and in the surface soil layer between different variants of pipe drainpipe spacing.

Agronomija