Retaining the clean and green image of Australian viticulture minimising the effect of agri-chemicals on the environment

Abstract

This research has provided data on the movement of key agrochemicals through air, soil and water within and beyond vineyards, which can be used to improve Best Management Practices that minimise the potential environmental impacts of vineyard spraying. An initial scoping study identified spray drift, leaching of agrochemicals through vineyard soils and the accumulation of copper in vineyard soils as being key issues to investigate further. Twenty-four agrochemicals were ranked according to their leaching potential, persistence in soil and toxicity.

Spray drift field trials showed that sprays leaving the vineyard as drift, or wasted as ground deposits, accounted for 7 - 31% of the sprayer output. This was influenced primarily by how well the air and spray plume were directed at that canopy rather than nozzle type. Fine droplets did not have high associated drift if they were applied using a well set-up, directed sprayer. Accumulation of copper was assessed in a national survey of nearly 100 vineyard soils. Copper concentrations ranged from 5 – 223 mg/kg (average 60 mg/kg). These values are lower than are reported in European vineyards (130 - 1280 mg/kg), but exceeded the ANZECC soil quality guideline value in 38% of the soils sampled. The potential impact of these concentrations on soil health, if any, is yet to be determined.

Leaching trials confirmed that time-integrated, solvent-filled, passive samplers are a costeffective tool for monitoring agrochemicals in drainage water, while ceramic and rhizon suction cups for extracting soil water were not suitable for this task. Field validation of a Pesticide Impact Risk Index (PIRI) model showed that PIRI could predict the leaching risk of several, but not all, agrochemicals from irrigated horticultural properties. With further validation, combined with the use of tools such as passive samplers, the PIRI model could potentially be used to generate vineyard-specific information about leaching risk.

Summary

Project summarises knowledge and practices for the choice of agrichemicals to minimise the environmental risk.