Farm Table says:
This report is provides the final results for the GRDC funded project CSP00146 field trials based in the high rainfall zone (HRZ) in the south-east (SE) of South Australia (SA).
This component of the project involved collaboration between CSIRO, Mackillop Farm Management Group (MFMG) and the South Australian Research and Development Institute (SARDI).
The field trials were located at Lochaber in the SE of SA.
The research aimed at answering the following three questions:
- Can a break crop be as profitable as wheat? This research project has shown that various break crops can be as profitable as wheat.
- Are sequences that include break crops more profitable than continuous wheat? Across all seasons (over a three-year period) the most profitable rotations tended to be those where initially a break crop was utilised, compared to continuous cereals. The sequences that included winter legume species as break crops were more profitable than continuous wheat across all years.
- What effects do break crops have on soil nitrogen availability? On average across all break crop seasons beans had the highest level of N fixation, averaging 13kgN/tDM produced.
The results presented are a culmination of three field trials initiated in 2011 and completed at the end of
2015. A three-year crop sequencing rotation was evaluated (break crop – wheat – barley), in three different field trials, each starting one year apart
The key findings of this research were:
- Including a break crop in the rotation can be as profitable across a range of seasons compared to a wheat on wheat rotation
- Greatest benefits of break crops will be obtained by sowing on break crop stubble first (i.e. before sowing wheat onto wheat stubble)
- The positive effect of a legume break crop can last more than one season
- Under favorable conditions the use of a legume break crop can increase subsequent crop yields greater than increasing that crops nitrogen inputs