Abstract:
There has been a heavy reliance on agri-chemicals in the Australian cotton industry over the past 20 years to increase production and profitability. The off-farm movement of these chemicals has created a number of environmental issues of concern for the industry (Edge, 1996). There is an urgent need for the development and adoption of management practices which reduce our reliance on chemicals and are agronomically and environmentally sound. Recent industry funded research has identified key transport mechanisms and highlighted the importance of storms and sediment in moving pesticides off-site. High risk periods include early season (when ground cover is low) and soon after chemical application (when field burdens of pesticides are high). Research in the grain industry has identified the capacity of stubble cover to reduce erosion and that winter cereals provide the most effective cover. Plot scale (<1ha) research in cotton found that a significant reduction in pesticide movement was achieved from surface treatments such as wheat stubble (Simpson et al, 1996 and Silbum et al, 1996). Our CRDC project commenced in June 1997 to develop management strategies to minimise offsite movement of pollutants at the paddock or farm scale. In particular, our goal was to apply the research findings with wheat stubble at the paddock scale and to assess the practicality and feasibility of this management practice.
