Information
The environmental fate of diuron under a conventional production regime in a sugarcane farm during the plant cane phase
Level 1 General Description
Purpose
This study measured the concentration of Diuron and its metabolites 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU), 3,4-dichlorophenylurea (DCPU) and 3,4-dichloroaniline (DCA) on a commercial sugarcane farm and in stream sediments in south-east Queensland.
Methods (Brief)
This study was undertaken on a commercial farm within the coastal Burnett catchment of south-east Queensland. The study monitored the concentration of Diuron and its metabolites within a 19 ha catchment. The sprayed area consisted of 5 rows, each 300 m in length with a slope of 1.4%.
Additionally, monitoring in a nearby stream was conducted over an approximate 5 km length below the catchment that drained approximately 3500 ha of sugarcane farmland. Diuron was analysed from stream sediment samples at a depth of 50 cm at 10 sampling locations.
Key Findings (Brief)
Over a 38 week period commencing in December 2005, concentrations of diuron within the 0-15 cm soil layer was >70% of the total detected diuron. Smaller amounts of 8-20% and 4-10% of the detected diuron were within the 15-30 cm and 30-45 cm layers, respectively. Greater than 65% of all diuron metabolite concentration recorded were DCPMU.
During two rainfall events where intensity and duration was approximately >20mm h-1 for >26 minutes, the total loading was >0.62% of the applied diuron. By the average concentrations of detected compounds and total volumes in the runoff events, their estimated total loadings were 2.6% of applied diuron.
The result of the stream sediment monitoring revealed that, while minor amounts of these compounds escape in farm runoff at commercial rates of diuron application, they are likely to accumulate in stream sediments at concentrations that may produce toxic responses.
Location
Investigations were carried out in the coastal Burnett Catchment of south-east Queensland, approximately 24.866ºS, 152.349ºE.
Related Studies
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