Getting the best out of oilseed rape requires investment in establishment according to one Suffolk farming business. Geoff Ashcroft finds out more.
For many growers, oilseed rape establishment has become a crude, low-cost process, driven by the desire to trim costs to the bone.
There are those however, who remain committed to making the most of the crop, and it begins with getting it off to as good a start as possible, to make the most of yield potential.
Suffolk grower Robert Rush falls into the latter category, and has sidelined his Vaderstad Topdown and Biodrill establishment system for one which offers more accuracy with seed placement and the ability to sow into clean soil.
He says: “We have been getting away with it for the last few years, but the time has come to put some effort into getting the crop off to a much better start. Our 2015 rape yield was bordering on poor, though flea beetle has been a serious problem.”
Based at Hall Farm, Shimpling, near Bury St Edmunds, Mr Rush and his team handle an 1,800-hectare workload as Apollo Farms. The predominantly chalky boulder Hanslope series clay soils play host to a mix of combinable crops and sugar beet, with oilseed rape accounting for 350ha.
“We have been growing oilseed rape for about 30 years, with varying degrees of success,” he says. “And in that time, we have tried most systems with a view to keeping establishment a straightforward and low cost process.
“But this year’s rape yield varied enormously, from two-4.5 tonnes/ha, with an overall average of just 3t/ha. This is unsustainable in the long-term.
“We’ve been looking for ways to encourage more plant vigour, and this has led us on a path to more organic principles. Stronger plants should be better placed to withstand the winter and also fight pests and diseases.”
He also intends to widen the farm’s rotation, growing rape once every six years.
The route to a more consistent yield target of 4-4.5t/ha, he believes, should mostly come from putting more effort into seed placement, rather than broadcasting seed into a trash-filled mix and hoping for the best.
“We don’t remove straw, so there’s a huge volume of chopped and spread material to incorporate and I believe mixing trash into the top layer of soil does not help rape to get off to a good start,” he says. “There is too much competition.”
The route to higher yield has seen the business invest heavily in a He-Va nine-leg sub-soiler equipped with AccuDisc coulters on a frame. These double disc coulter units open a seed slot in the soil.
Each coulter assembly is spring-mounted on a parallelogram frame, enabling ground contours to be followed, while achieving a consistent seeding depth. Discs are followed by a rubber press wheel, which serves to close the slot and consolidate the surface.
Developed as a one-pass system, the sub-soiler also carries a slug pellet applicator and Nitrojet liquid fertiliser system. The latter affords nutrient placement, inline with the coulters, at the time of sowing.
A 1,600-litre liquid fertiliser tank sits on the tractor’s front linkage, with seed and slug pellet hoppers carried on an extended beam at the back of the implement.
“Where we had been broadcasting rape seed into a 6in mulch of soil, straw and trash, we are now placing seed into a much cleaner strip of soil with the help of low disturbance legs and disc coulters,” he says. “The legs seem to sweep trash to the sides, leaving a broken surface, which is firmed by the press roller ahead of the coulters.
“Adding liquid fertiliser and a dose of slug pellets too, all done in one pass, is the icing on the cake,” he says. “Once sown, the field is rolled.”
Without incorporation of trash, this latest establishment mechanism is one that could place higher demands on the combine’s chopping and spreading capability. And all eyes are on surface residues, which he sees being utilised by worms over the winter.
Mr Rush says the He-Va system has now saved a pass, and output at 40ha/day is broadly similar to his previous Topdown/Biodrill system.
“But we would always have to follow the Topdown with a press, and then often roll the field afterwards,” he says. “And where we needed to pull the 6m Topdown with our Quadtrac 550, we can handle the 5m He-Va with our Xerion 3800. So we’re saving on fuel too.”
Seed rates have been reduced too. The greater planting accuracy of disc coulters means the former 5kg/ha seed rate has been lowered to 3kg/ha, and sowing at wider 55cm row widths is also expected to encourage a greater number of pods.
“If this system proves to be successful, we’ll probably try 2.5kg/ha next year,” he adds. “There is an optimum seed density, and my target is to get 20-40 plants per square metre.
“Seed placement has been great, and the way the disc system operator means if there is a blockage – perhaps from being in wetter conditions – there is a way the seed can still get out. It won’t be planted with quite the same accuracy, but it won’t be missed.”
Greater accuracy though, comes at a cost. And the price of the He-Va machine has been considerably higher than any other oilseed rape establishment system previously used by Apollo Farms.
“It’s not a low-cost system. We’ve gone against the grain a bit with this one, and depreciation will be high,” he says. “But it’s a long-term purchase and the costs will be spread over a fair few acres over the next 10 years.”
Having carried out 15ha of supplementary contracting with the new machine, he anticipates a few more hectares for 2016, which should also help to offset its purchase price.
“There is always additional pressure to do the job properly on other people’s land,” he says. “But I’m confident of the machine’s ability to perform, and it will have more than one role in our machinery fleet.
“If we swap the low disturbance legs for proper sub-soiler legs, we can put the He-Va behind the Quadtrac and go sub-soiling.”
When it comes to running costs, he says the first set of points gave him a shock.
“Wearing metal costs were heading for £13/acre, so I hard-faced the second set of points in the workshop to try and reduce the running costs.”
He says there have been a few teething troubles with the machine too.
“But Opico and my local dealer TNS have both responded well to my concerns and to getting us going quickly,” he says. “There are some winter modifications to carry out, and I’m confident these will improve the machine’s durability.”
Having done his homework over the last couple of years and considered Mizuri, Stripkat and even home-built kit in the workshop, he remains steadfast with his buying decision.
“We can’t over-estimate the value of getting the crop off to a good start, and I see this as an essential part of achieving consistent yields,” he says. “Getting 5t/ha would be quite an achievement. It’s not impossible, but it is a long way off. We certainly couldn’t get it on this land using the Biodrill.”