GCTV15 Stubble Height Pt2
Narrator: Tony Crowley In part one of our report on GRDC's Stubble
height and crop emergence trial at Downside in southern NSW we saw the dramatic difference
in crop emergence. On the left of screen an average 30 plants
per square metre and on the right just half that number.
The difference was, the canola on the left was planted where wheat had been harvested
at a height of 60 centimetres and the standing stubble burnt prior to canola being sown.
While on the right, the header cut much lower at 15 centimetres and the stubble was spread
and retained.
Chris Minehan: Farm Consultant, Rural Management Strategies, Wagga Wagga NSW
And it's this chaff even more than the standing stubble that I think is hindering that emergence
of the canola.
Narrator: In addition two other treatments were included
in the trial. A high cut without a follow-up burn, which
resulted in 24 plants per square metre. And a third high cut followed by a K-line
trash cutter. It resulted in 16 plants per square metre, similar to the low cut and retained
stubble treatment. The entire canola crop had been sown using
a single disc seeder.
Chris Minehan: The smaller the seed the more vulnerable it
is to desiccation by hair pinning or poor contact with the soil.
Narrator: In those treatments were stubble load was
higher the disc seeder wasn't always able to get the desired seed soil contact. The
heavy load of chaff, straw and trash resulted in the disc wedging straw into the narrow
furrow creating a barrier between the canola seed and the soil. What's known as hair pinning.
Chris Minehan: There's always a lot of consideration and
discussion around the best sowing system to use, disc verses tynes, level of disturbance,
row spacing things like that, a trial like this is valuable in terms of quantifying how
one of those elements being the choice to use a disc here interacts with different stubble
treatments.
Narrator: As growers start to turn their attention to
harvest, this trial is producing timely data for decision-making. What's the best cutter
bar height to optimise cereal harvest efficiency and yield. And what's the most appropriate
stubble management strategy for maintaining the benefits of a retained stubble farming
system while keeping in mind how seeding machinery will cope with potentially high stubble loads.
Real issues requiring local solutions.
Chris Blanchard: Deputy Chair, GRDC Southern Panel
A lot of these trials are being conducted by farming systems groups in the regions addressing
their problems and the great thing about that is that if growers can actually see the results
of these trials in their region then there's a really good chance that they are going to
adopt any practice change that's recommended by that research.
Narrator: Early adopters of this trial's outcomes could
potentially improve farm returns as soon as this harvest.
As the trial continues additional research data will be added including canopy temperature
measurements and frost events, which are being recorded in collaboration with NSW DPI for
GRDC's Frost Initiative. After this canola is taken-off there'll be
a different stubble scenario to add to the research data and to the outcomes of the broader
five-year national stubble initiative, which the GRDC has invested in.
Chris Blanchard: The great thing about the variety of trials
that we're doing in the Stubble Initiative is that we can actually learn from the lessons
of people in other regions. So those results can be adopted in the southern region or it
might be the northern or western region so there's plenty that we can learn from each
other.
Narrator: The southern edition of September's Ground
Cover has a report on this project and for more information about the research and its
outcomes go to Farmlink Research and under projects look for Retained Stubble.
Ends