Innovative farmers have come up with many workshop ideas to establish oilseed rape, and one design is also offering the flexibility to broadcast other sma
ll seeds and granules, reports Jane Carley.
Oilseed rape is one crop that keeps farmers guessing and Martin Downes, manager at Squab Hall Farm near Leamington Spa, Warwickshire, is no exception.
“You can spend a lot or as little as possible on establishment and if it is going to grow, it will do so regardless,” he says. “
At least you know by October so you can grow something else.”
That said, given the positive prices, he is among the band of growers looking to increase the acreage for 2023, up from 50 hectares this year to 75-80ha.
“It is all conventional varieties this year, but we have also looked at going 50 per cent hybrid.”
For this year’s crop, he has dabbled with a different approach, using a home-built broadcaster to put the seeds into the previous crop pre-harvesting.
The project started with a Berthoud trailed sprayer chassis sourced from local dealer John Rhodes, its 24m booms extended to 30m with 3m breakbacks added to each side. A Techneat Twin Air applicator was then added, with hydraulic drive to the fan and metering via twin rollers. Techneat also supplied the pipework from the 250 litre hopper to the distributor heads on the boom and from the heads to the outlets, plus the 50cm-spaced broadcasters themselves. Currently at 1.82m centres, the axles will go out to 2.00m for this season to match the tramlines.
“It also gives me a high output Avadex applicator, and can be used to broadcast cover crop seed into standing crop,” adds Mr Downes.
“You can get a kit for a self-propelled sprayer, but we felt the tank would be too big for our trailed Horsch and place additional strain on it so a dedicated applicator was the solution.”
Building a mounted version was also considered, but the location of the boom folding around the cab ruled it out.
“Our oilseed rape was planted during July in 2021 – everything that was drilled failed and everything broadcast came through,” says Mr Downes.
“Rain was forecast but never came when we drilled in late July after winter barley; the rape that was underneath the standing crop landed on damp soil and got away well. When we came to combine, we left a long stubble to deter pigeons.”
Also, where the combine had tracked during harvest, the improved seed to soil contact meant strong early establishment, but without the standing stubble, these areas were later decimated by pigeons. The emerging shoots ran along the ground in the crop, suggesting that stem canker might be an issue, but these thinner shoots grew into sturdy stems with plentiful branching.
“Broadcasting does require higher seed rates – 7.5- 10kg/ha, compared to 2-3kg/ha when drilled. With OSR seed at 15/kg it would not be viable, but with farm saved seed at 0.60-0.70/kg, the cost is 7/ha,” he says.
Mr Downes comments that it also gave him some flexibility, planting into spring barley in the second week of August before harvesting and then baling the straw.
“There was no impact from the balers except where the trailers were loaded,” he reports.
Taking Avadex broadcasting in-house gives peace of mind on timing compared to relying on a contractor, Mr Downes notes.
“Plus the workrates are a lot higher than the typical 12m outfits on offer; and because the applicator is working in the tramlines so there is no vehicle running over the field in the damp conditions that are ideal for the product. The only limitation is that the granules will no flow if it is raining heavily. The other routes we could have gone down were to have the applicator on the drill, but it then needs rolling which is not always possible.”
He is looking to plant some cover crops ahead of harvest: “I will need to find a seed that will go through the rollers, such as a mustard-type mix, but once it is in and the harvest is done, the field’s finished until I am ready to plant a winter or spring crop.”
Total cost of the applicator came to 22,000, based on the second hand chassis and new hopper and pipework from Techneat.
“Looking at the oilseed rape crop I would expect it to match our usual 3-5-4t/ha yield, but our establishment costs will be considerably less than for drilling, and in a more difficult year that will count for a lot.”
