Environmental fate of pesticides used in Australian viticulture ii: Behaviour of dithianon and vinclozolin in an acidic soil of the rutherglen region of Victoria, Australia

Abstract

The movement of the fungicides dithianon and vinclozolin through small, undisturbed soil cores (of dimensions 15 × 15 × 15 cm) was investigated. The cores were extracted from the topsoil and underlying subsoil of a research station paddock approximately 10 km SE of Rutherglen, Victoria. The soil above the bedrock consisted of a thin (20 cm) layer of red‐brown, acidic surface soil with a moderate organic carbon content (1.2–4.1%), below which was yellow‐brown bleached clay containing substantial amounts of buckshot (iron rich nodules 3–8 mm in diameter). Surface fluxes of pesticide were applied at the maximum recommended application rates to the centre of the cores, which were then irrigated. Pesticides were extracted from the leachate and soil using solid phase extraction (SPE) and residues determined by HPLC. No dithianon was detected in any leachate. Dithianon was found immobilised in the top 2 cm of the cores (7–38% applied dose). Approximately 5% of the applied vinclozolin leached through the topsoil core. Approximately 8–10% of the applied vinclozolin leached through the subsoil cores. Between 5–10% of the applied vinclozolin was found immobilised in the top 2 cm of the cores.

Keywords:

• Pesticide mobility
• heterogeneous flow
• acidic soil
• dithianon
• vinclozolin
• solid phase extraction

Notes

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