By Paul Breust, SFS
- Seed in the Rapid disc treatments was placed deeper than ideal resulting in lower plant establishment.
- Tyne seeder in burnt stubble was significantly higher in yield to all disc treatments and the tyne stubble incorporated plots. No significant yield difference between tyne stubble burnt and tyne stubble retained plots.
- NDVI for the tyne stubble burn was significantly higher than the all other treatments.
- Establishment was poor overall and highly variable resulting in large trial CV for establishment.
- Ryegrass was a problem with numbers ranging between 140-198/m2, treated successfully with Roundup Ready herbicide.
Establishing canola in retained cereal stubbles presents many challenges to growers. The GRDC stubble project is aiming to develop production systems that maintain or increase profitability when retaining stubbles.
This trial was implemented to assess the impacts of three stubble management practices:
- Stubble retained and crop direct drilled into it
- Stubble incorporated before sowing
- Stubble burnt before sowing
Seeding equipment has a wide range of trash handling capabilities. Disc seeders are considered better suited to trash handling than tyned seeders. To compare the production differences between disc and tyned seeders we established a trials using both implements.
To measure the impact of seeder type in a range of stubble management treatments.
a) Knife point and tyne trial seeder, Southern seeder, developed for trash handling.
- Incorporate using Vaderstaad Topdown
- Retain direct drill
b) Vaderstaad Rapid disc seeder.
5. Incorporate using Vaderstaad Topdown
6. Retain direct drill
Single block, three replicates, fully randomised.
Unfamiliarity with the operation of the Vaderstaad Rapid disc contributed to poorer establishment in this treatment. The Vaderstaad Rapid has the option to cultivate in front of the seeding disc’s which was engaged in this trial. In hindsight this cultivation was detrimental to seed placement which is critical for Canola.
The tyne burn and tyne retained stubble were not significantly different for yield however the tyne retained was significantly less for NDVI than the tyne burn treatment. NDVI is “normal differential vegetative index” and is a good indicator of dry matter production. While the NDVI was lower the fewer number of plants could have compensated for this by producing more seeds per plant.
This trial has provided us with a preview of the potential of canola crops established in retained cereal stubble and the more traditional practices of burning and incorporation. It has clearly demonstrated the potential problems and difficulties in running trials of this type. It has allowed us to improve the design and eliminate treatments from the study. It was encouraging that the tyne and disc retained stubble treatments were not significantly different for yield when compared to the burnt treatments for both seeders.
Large scale on farm trials will be conducted in 2015 using commercial disc and tyne seeding equipment.
SFS gratefully acknowledge the generous co-operation of Neil Vallance and family at this site. Many thanks to Swayne and McCabe for use of the Vaderstaad Topdown and Rapid disc seeder. Seed of RT 525 was donated by Pacific Seeds (now Advanta Seeds).
The stubble project – maintaining profitable farming systems in Victoria and Tasmania with retained stubble (project number BWD00024) is funded by the GRDC.