Riverine Plains Inc recently ran a series of discussion days and field walks which focused attention of one of this year’s most prevalent sowing issues - the difficulty of managing high cereal stubble loads in direct drill systems.
The on-farm days were run at Oaklands, Dookie, Boomanoomana, Rutherglen and Culcairn and attracted over 200 local farmers. The Dookie meeting was attended by over 70 people, demonstrating just how topical the issue was!
Out of the farmer discussions came the following observations:
- Stubble height is the most important factor. Stubble should be no longer than the distance between rows.
- Coulters are good but don’t seem to solve all issues in all cases. The wave coulter was generally preferred.
- Straw cutters, stubble crunchers, straw choppers, windrowers and headers were all used to manage straw after harvest. The consensus was that it needs to be soon after harvest and dry if possible. It was noted that if headlands and around trees in paddocks were cut shorter this helped trash flow immensely due to lack of inter-row sowing. A locally operated stubble mulcher was considered to do an excellent job. Windrowers with the mats pulled out, stubble crunchers and a K-line straw cutter were also considered to do a good job in dry conditions. It was noted that in most cases growers had to wait for contractors or machines to become available, thus with the wet summer some of these machines didn’t work as well.
- People generally had fewer problems during the day but most people struggled after 5pm as the stubble increased in moisture and started to bend and catch.
- 2cm GPS accuracy with auto steer is a vital component to the success of inter-row sowing (but need to “nudge” the GPS before you start sowing!).
- Steering wheel driven autosteer wasn’t good enough for reliable inter row sowing.
- The headers ability to spread trash full width of comb is vital for sowing for the following year.
- The direction of travel of the seeder needs to be followed year in, year out, to overcome any unevenness between tine or disc spacings on the seeder. It is better if the seeder follows the direction of the header too.
- Keep as much traffic (eg. Chaser bins & trucks etc) on tram tracks as possible to reduce the amount of stubble pushed over.
- Some growers are sowing pulses and canola on 24” row spacings to help with trash flow. Growers don’t seem to think that they will have any yield penalty doing this.
- It was noted that disc machines handled heavier stubbles better than most tined machines, but if tine machines were fitted with a coulter that proved very effective. NB. Important that there is enough room between coulters and tines to prevent a build up point.
- Some growers fitted coulters or discs units on wheel track area of seeders to overcome knock down straw.
- Summer weed control is important to achieve effective trash flow.
- Circular pipe on tine shanks decreases catch points (ie poly and cable ties, gal pipe, exhaust tube). If installed over the top of the point assembly, it also allows caught material to drop off when machine is lifted.
- Tine layout on some seeders required improvement due to some press wheels being too close to a tine (thus becoming an area which easily blocks with straw).
- A second cutter bar fitted to the rear of header front to cut stubble 6” shorter, was put forward as an idea and apparently trialed in WA and QLD.
- Livestock were considered to result in greater trash flow issues if allowed to graze paddocks.
- Tyre pressure of seeders is important to reduce crabbing of seeder.
- Surprisingly, some people experienced less problems with sprayed off autumn weeds amongst stubble. It seemed to retard and catch the loose rotted straw and keep it on the ground.
- Broad leaf crops don’t have the same level of vigour when shaded by E-W row orientation stubble.
- Growth regulators were talked about but generally regarded as a hit and miss option.
- Micro organism liquid enhancers were considered hit and miss options.
For further information on the days, please contact Fiona Hart at Riverine Plains Inc on 03 5744 1713.