No-tillage adoption decisions in southern Australian cropping and the role of weed management

Adoption of no-tillage sowing systems has increased rapidly in many Australian grain growing regions over the past decade. The extent of herbicide resistant weed populations in these regions has also increased over the same period. A survey of growers in the South and Western Australian cropping regions was conducted to identify opportunities for more effective tillage and weed-related extension. Trends in sowing system use are determined, as are growers' perceptions of the long-term effects of no-tillage on herbicide costs, herbicide resistance, and soil erosion. The results suggest a major expansion in the adoption of no-tillage sowing in most South Australian cropping regions over the next 5 years, although growers expect increased herbicide costs in no-tillage systems and an increased risk of herbicide resistance. Herbicide resistance and weed control issues are the main reasons given for reducing no-tillage use. A key research and extension challenge is to develop and implement weed management strategies that are able to sustain long-term no-tillage use in a cropping environment where growers place a high value on the soil and production benefits of no-tillage, but over-reliance on herbicides can rapidly lead to resistance in major crop weeds.