Lysimeter studies of the experimental insecticide BAS 263 I.
Abstract For investigating the leaching behaviour, distribution, and metabolism of the experimental insecticide BAS 263 I within one year following application a lysimeter study with undisturbed soil monolith using the radiolabelled compounds was performed. This was achieved by monitoring the leaching water, and by analyzing radiolabelled residues distribution in the 1 m soil profile and in plants. The soil monoliths were characterized chemically and microbiologically. Concentrations exceeding 0.1 μg/1 of the insecticide itself or of known metabolites were not found at any time in the leachate. One year after application, more than 96 % of the persisting radioactive material were detected in the 0 ‐ 40 cm soil layers as polar non‐extractable residues. The insecticide itself was not detected in soil at a limit of 1.8 μg/kg. The total residues in the cultivated crop, especially in the edible parts of the plants, were below 1.3 x 10‐4 μg/kg, calculated for the molecular weight of the a.i. and corresponding t...