A small however rising military of combinable crop growers are resorting to medieval strategies in their battle on weeds, shunning fashionable chemical weapons in favour of decapitating their botanical enemies.
It would possibly sound like Putinesque barbarism, however chopping off the heads of perennial troublemakers comparable to blackgrass, ryegrass and brome is quick changing into the one efficient approach to skinny out seedbanks in fields overrun with herbicide-resistant weeds.
That’s the method German maker Zurn has taken with its Top Cut Collect (TCC) – a weed harvester initially designed by French farmer and inventor Romain Bouillé.
See additionally: How mix add-ons will help slash weed seed unfold
As the title suggests, the TCC is towed by means of a discipline to chop and acquire any crops that stand happy with the crop, notably people who don’t reply to traditional agrochemicals – and that are so considerable that hand roguing can be impractical.
Zurn Top Cut Collect
- Width 9m or 12m
- Cutting peak 30-150cm
- Working velocity 3-8kph
- Hydraulic move required 80 litre/min
- Hopper capability 7,000 litres
- List value £92,000
One would possibly anticipate its most evident calling to be natural methods, the place mechanical weed management is commonplace apply.
But thus far, demand has come solely from standard growers seeking to overcome resistance issues and handle the rising price of chemical compounds.
However, it’s definitely no silver bullet to herbicide-resistant grassweeds, and the injury to this yr’s crop can have already been finished; the soil vitamins stolen way back.
The clear-up course of is more likely to be lengthy and sluggish, however eradicating the seed-laden heads is a minimum of a primary step in bettering discipline hygiene.
One apparent draw back to the TCC is that’s doesn’t have the all-season versatility of a sprayer, with its working window restricted to a few discipline passes in the course of the late spring/early summer time.
That will make its close to £100,000 record value slightly onerous to justify, even for the most important and most properly-heeled estates.
As a outcome, most consumers are more likely to be contractors – comparable to Kevin Smith, who invested in a TCC for his Pasture Care enterprise based mostly in Thame, Oxfordshire, after seeing it at Lamma.
It was delivered in September and sat idle for six months, however is now in its peak season as downside weeds hit their early summer time progress spurt.
How extensive is it?
© MAG/Oliver Mark
Mr Smith opted for the biggest mannequin out there, which carries a 12m reciprocating cutterbar on gullwing mountings.
“The 12m model is the most important that Zurn affords in the UK,” he says. “An 18m mannequin has been made, however solely the person that invented it’s got one and I’m not satisfied it might work – fields aren’t flat sufficient, and the lower can be too uneven.”
The modest working width – by sprayer requirements, a minimum of – implies that on 24m tramlines the tractor and implement should type their very own wheelings on each different go.
The ensuing injury equates to an estimated yield hit of roughly 3%, which is a fraction of the hurt more likely to have been attributable to a major blackgrass infestation.
Guidance is important – in Mr Smith’s case Greenstar cellular RTK with a 6000-sequence dome and Autotrac Universal 300 steering wheel motor.
At £11,000, it price nearly as a lot because the tractor charged with operating it – a 2004 Valtra M130.
Mr Smith says: “The fantastic thing about the Valtra is that it has a brief wheelbase, it’s manoeuvrable and is light-weight, which minimises crop injury.
It additionally means I can get away with the narrowest tyres out there – a £4,500 set of second-hand 300/95 R52 and 270/95 R38 row crops.”
© MAG/Oliver Mark
Combined with a 40kph transmission and suspensionless cab, you’d anticipate the experience to be hideous, however Mr Smith says it’s “surprisingly snug”.
The TCC additionally runs on supermodel-skinny 210/95 R44 tyres, set at a 72in monitor width to match the tractor, however they’re fitted on a inflexible axle, which may trigger pointless crop injury when turning.
Crop dividers can be found however are not often essential now that extensive wheat row spacings are commonplace.
The greater wheels additionally increase the tractor’s floor clearance by 30cm and, along with a easy foresty-spec underbelly, hold disturbance to a minimal, lessening the danger of untimely seed shedding.
Mr Smith says: “Gently brushing the crop with the beneath of the tractor really works in my favour early in the season, because the blackgrass springs again up and straight into the cutterbar, however floor clearance turns into extra necessary as harvest nears and the danger of seed shedding rises.”
Destroying the weed seeds
Weed seed heads are collected in the 7,000-litre hopper which, as soon as full, is emptied right into a telehandler bucket. There could be numerous biomass to do away with, with the worst infestations filling the hopper on each discipline bout.
The best technique of disposal is to burn it. Trials recommend that composting the fabric is tougher, as excessive temperatures are required to reliably kill the seed.
How low can it go?
Cutting peak ranges from 30cm to 1.5m, however it comes right down to how aggressively the farmer needs to sort out downside weeds – and whether or not they’re keen to take a success on crop yield because of this.
“One buyer wished the highest of his oat crop taken out to permit me to chop as a lot of the blackgrass as attainable, and it bounced again surprisingly properly,” Mr Smith says.
“But others are reluctant to threat any lack of yield, so I attempt to work inside the parameters they set.”
Kevin Smith © MAG/Oliver Mark
In most circumstances, the purpose is to run the dual reciprocating cutterbar as near the highest of the crop because the operator dares.
Early trials by Niab recommend it’s as much as 90% environment friendly in the gathering of blackgrass heads when employed in this fashion, though the timing – pre-shedding – is crucial.
Opting for a double cutterbar is alleged to cut back losses forward of the conveyor, and the hydraulic drive permits for the velocity to be altered to go well with the situations.
Operators can even tweak the pitch of the slicing desk, whereas peak is ready on the tractor’s linkage and a jockey wheel on the finish of every wing.
The lower seedheads are brushed onto a conveyor by a helical reel that whizzes round noticeably faster than that of a mix.
Its place and velocity could be altered – too quick dangers flicking seedheads over the again of the desk; too sluggish and so they would possibly fall off the entrance of the cutterbar.
They are then ferried alongside 40cm-deep PVC conveyors to a central elevator and up into the 7,000-litre hopper.
What is output like?
To the trendy “toes up, auto-steer on” tractor driver, the handbook peak management – the place one false transfer may obliterate a crop – is more likely to be a frightening prospect.
Typical working velocity is about 6kph, depending on crop uniformity (and subsequently the frequency at which the operator has to change the cutterbar peak) and weed density.
“In some locations, the blackgrass is so rife that it may be onerous to see the wheat beneath, and that makes peak management an actual problem,” Mr Smith says.
© MAG/Oliver Mark
“My greatest day thus far was 150 acres [60ha,] and my worst was 30 acres [12ha] in an uneven crop with a heavy yield of blackgrass.
“In these conditions, I’ve to make tons of of choices a day – slicing peak, working velocity, the place to chop, the place to unload, and so forth.”
“As a outcome, it’s fairly tiring, so I prohibit myself to 10 hours a day. A lapse in focus may have a serious influence on crop yield or mangle the machine, so it’s not well worth the threat of working lengthy hours.”
“I cost a day charge – £2,000 for the primary day and £1,500 thereafter – which implies I can focus totally on doing a superb job, slightly than maximising my output.”
When is greatest to do it?
Yield injury to the present autumn-sown crop will have already got been finished, so the timing of the TCC go must maximise seed seize.
Mr Smith’s season began on 18 May in a wheat crop on the Fens, and he reckons he could be operating properly into July – relying on the climate and the impact it has on weed seed shedding.
“I in all probability lower some stuff a bit early this yr, however it’s such a brand new method that there’s no established method of doing issues. Everyone has an opinion, however nobody is aware of who is true.”
According to Will Smith, senior trials supervisor at Niab, slicing too early might encourage the weed to tiller at its base after which produce heads that aren’t tall sufficient to be catchable.
“Early June might be one of the best time to reap the weed heads, however that may change yearly.
It’s about concentrating on the expansion stage of the weed, slightly than the crop, and hanging when the peak distinction between the 2 is at its most.
“That’s simpler for some weeds than others – blackgrass, Italian ryegrass and wild oats have a tendency to face above a cereal crop and needs to be pretty straightforward to seize.
Brome, by comparability, sits in the cover and is surprisingly quick – making it far more durable to chop out successfully.”
© MAG/Oliver Mark
Growers may also profit from tweaking their rotation and institution system to enhance the efficacy of mechanical weed management, says Will.
“Anyone transitioning to no-until is clearly making an attempt to forestall the construct-up of seed in the topsoil, and the mix of diminished cultivations and use of a harvest weed management technique will help minimise seed return.”
Another possibility could be to develop a shorter crop, comparable to linseed, that might be dwarfed by the blackgrass – thus making it simpler to reap.
To prolong the machine’s transient working season, Mr Smith received a neighborhood fabricator to suit a tow ball and electrical connection to the rear of the machine.
This permits him to tow a caravan, increasing his territory properly exterior of Oxfordshire with out being reliant on another person for transport.
“Customers should suppose the circus is popping up, however as soon as I’d purchased the machine, I realised I’d must journey an extended approach to hold it busy and logistics have been going to be a problem.
“The diesel value has additionally gone by means of the roof, and it’s simpler for me to hold instruments and spares, so the system works properly.”
Niab is conducting trials of a 12m Top Cut Collect at its website in Cambridge, concentrating on brome, blackgrass and several other broad-leaved species throughout a sequence of crop plots.
According to senior trials supervisor Will Smith, mechanical approaches to weed management may turn out to be an necessary a part of any rising technique – however is not going to be a standalone resolution.
“It’s vitally necessary that a lot of the weed management in an autumn-sown crop is accomplished earlier than Christmas to minimise the yield influence,” he says.
“If the tip purpose is 90% management then you definitely wish to be hitting a minimum of 60% of that focus on earlier than the flip of the yr.
“Harvest weed management methods may then take care of any remaining downside areas, however with out that early management, weed density will adversely influence crop yields.
Niab is testing each the TCC and a mix-mounted weed seed mill, which have each proved efficient at hitting totally different species late in the season.
“The Top Cut Collect fits early shedding weeds comparable to blackgrass and we discovered it was capable of scale back the variety of heads by 73% in a crop of winter wheat.
“By comparability, the seed mill had no impact on blackgrass prevalence in the next crop as there was so little seed left on the crops at harvest.
“In brome the alternative was true. Brome holds on to its seed for much longer and, because of this, the mix mill led to an 83% discount in weed seeds in the next crop – but the Top Cut Collect had little influence.”