Using canola as a dual-purpose crop for providing a break for weed and disease control
Dual purpose cereals (cereal crops grown for both grain and grazing) have been a fundamental component of Australian mixed farming operations in southern Australia in recent decades. In particular, dual-purpose wheat has been successful and widely adopted. However, the success and intensity of its use in high rainfall zones led to increasing root and leaf diseases as the strategy did not allow for a break in the continuous grass-based system of cereal and grassy pastures.
In the early 2000’s, CSIRO researchers hypothesised that canola could be another dual-purpose crop option providing a break for weed and disease control while also enabling increased flexibility and profitability in farming operations. It was theorised that canola could be sown-early and grazed during winter with no cost to subsequent grain production, providing a profitable break option in mixed farming systems.
Translating dual-purpose canola use into industry
CSIRO researchers with financial input from research partners, conceived, developed and successfully translated the concept of dual-purpose canola into southern Australian mixed farming enterprises. CSIRO developed robust dual-purpose canola management guidelines by applying experimental understanding to scaled up crop and whole-farm models and to commercial case studies.
Commercial adoption took place within five years of the commencement of research and today the practice is an integral part of the farming system in southern New South Wales. The fast adoption is credited to the significant and consistent research-industry engagement throughout the research and development phase.
Weed and disease control and increasing crop yield
CSIRO’s dual-purpose canola management technique has been widely adopted across southern NSW and in other mixed-farming pockets of southern Australia in Victoria, Tasmania, South Australia and Western Australia. At least 150,000 hectares of canola is estimated to have been grazed in southern NSW in 2021, and up to 200,000 hectares nationally.
The strategy is profitable at the individual paddock scale because grazing either comes at no cost to grain production, or the graze-grain income exceeds that of grain-only crops. The inclusion of dual-purpose canola also provides wider system benefits to underpin weed and disease control in dual-purpose cereal crops, and for perennial pasture establishment. Ultimately, it’s inclusion in the farming system mitigates risk and increases enterprise flexibility.
We estimated that the net present value of benefits (for FY2006-FY2025) of dual-purpose canola research and adoption would be approximately $1.628 billion (or a benefit cost ratio of 152) in2020/21 dollars, at a 7 per cent discount rate and given model assumptions.