| Abstract | The fate and persistence of a number of the key pesticides used in Australian sugar production have now been quantified for a range of soil types and conditions, In general there is no evidence of season-to-season build up in the soil from annual pesticide applications, However the herbicide diuron was shown to be highly persistent on the red ferrosol (krasnozem) site, Calculated dissipation rates (DT50) were used to establish risk windows for potential off-site losses, Sampling of the soil profile showed that most of the applied pesticide remained (and dissipated) in the upper 15 cm, Rainfall and surface runoff were measured throughout the project with samples of runoff collected throughout runoff events, Pesticide concentrations measured in runoff from the end of furrows were relatively high at times, particularly when runoff events followed shortly after application, This fouryear study highlights the need for careful management of application timing and chemical selection, particularly in areas close to waterways and sensitive habitats, Limited studies on the effect of pesticide application on trash, suggest that trash retention reduces the pesticide concentrations entering the soil and provides conditions for reduced off-farm losses, Information obtained will be incorporated into improved management guidelines, |
