Getting grass and fodder crops established in rock and stone is one of the major challenges for New Zealand’s livestock pioneers farming on the limits of what we’d consider feasible. United Kingdom-based Nick Fone visited this country last year and talked to a drill manufacturer who has made his business to build bespoke seeders for just such conditions and an Otago contractor who puts them to the test.

For years New Zealand has been widely regarded as something of a mecca for direct-drilling enthusiasts. It’s no surprise really given the country has been responsible for so many of the innovations seen on the no-till seeding rigs that have come and gone over the years.

Duncan box drills in the 1970s, Aitchisons in the 1990s and most recently the ultra-heavy, ultra-expensive Cross-Slot – machine viewed by many ‘never-brown’ zealots as the ultimate answer to all the issues associated with direct-seeding.

But aside from these big names, driven by an underlying sense of natural national ingenuity and vast variations in climate and conditions, there are a few other seeder specialists working away quietly in NZ– Taege, Thian-Drillrite and Allen, to name just a few.

At Ashburton, Allen Custom Drills is a small company that, as the name suggests, specialises in bespoke-built seed drills.

It all started in the late 1990s when Canterbury farmer and contractor Dave Allen decided he needed a crop establishment tool of the type that simply wasn’t available to buy.

Running a Great Plains CPH seeder at the time, he wanted to stick with the concept of a triple disc but make a machine that was stronger and cheaper to run.

Although the concept worked, the Great Plains box-drill metering system wasn’t suited to handling small seeds such as clover, turnips and kale – mainstays of the South Island’s burgeoning milk-from-forage dairy industry.

So he set about designing and building his own heavy-duty drill rig. The drawings were scratched out in chalk on his workshop floor and quickly the first Allen Custom drill took shape with an Accord pneumatic metering system and triple-disc openers.

It proved a success and quickly word got out across Canterbury with other contractors asking Allen to put together something similar for them to buy.

“Dad’s drills rapidly got a reputation for being built like brick out-houses and quickly it became apparent that if it was to become a serious business it would have to be more than a bloke-in-a-shed operation,” Craig Allen explains.

“So having been working overseas, in 2006 I came back to help turn it into a commercial affair. I taught myself how to use CAD software and started to bring a few, guys in to help with fabrication.” Then his partner Deb joined up and that streamlined the operation. Not only did she bring a level of organisation they lacked but she wasn’t afraid of getting her hands dirty.

“We’d often find ourselves in the workshop late at night putting drills together as demand snow-balled.”

The couple bought the business from Dave eight years ago and moved into a set of purpose-designed buildings in Ashburton. Manufacturing is still small-scale with a team of eight building individual drills to customers’ individual specifications.

Small is good

Being small is what keeps the couple grounded and they have no huge ambitions for global domination, Deb says.

“That said, a quarter of our machines now get exported to Australia and we’ve got interest from the US as well as Europe. Although every drill is built to order, we now have a range of five basic models that customers can spec. to suit their needs.”

The first is the H-D-series (Heavy Duty) – a heavy-frame, flat-land direct-drill. It employs the triple disc concept – a ‘turbo’ opening disc followed by a twin disc-coulter.

The C-D-series (Contour Drill) uses those same basic principles but all the elements are grouped in a more compact, close-coupled package, making for a machine much better suited to undulating terrain. It’s now the company’s best-seller, thanks to its contour-following abilities.

The P-D (Packer Drill) is a min-till drill which uses similar twin-disc coulters but has two rows of scalloped cultivator discs up front to produce a shallow tilth ahead of the seed, much like a Vaderstad Spirit or Horsch Pronto.

The E-D (Economy Drill) is a stripped down, simple rigid frame machine with many features shared with the rest of the line-up but without any frills.

Finally there’s the T-D series (Tyne Drill) which uses simple T-Boot points on coil tines, rather than discs.

All use Accord metering systems and RDS Artemis electronic rate control with the option of a twin-hopper grain and fertiliser variant – 90% of Allen drills go out in this format.

The tool-bar itself varies depending on working width – from 3m to 12m. Whether you opt for wavy ‘turbo’ opening discs or banks of scalloped cultivator discs on the P-D, all are mounted to the frame via a rubber ‘sausage’-type suspension system of the sort you’d find on many other machines on the market.

The wing sections have an active, pressurised hydraulic system to ensure accurate penetration and placement on undulating ground. Meanwhile the twin-disc coulters are individually mounted on simple parallel linkages with following press-wheels that serve to maintain seeding depth as well as seedbed consolidation.

Finally there’s the Allen trademark – the option of a Hiab crane to make the rig a self-sufficient, self-loading outfit when it’s out in the field.

Putting it to the test

One man who’s got more experience of the Allen concept than anyone is North Otago contractor David O’Neill.

Running three of the company’s bespoke-built drills, his business does some 4000-4500ha of crop establishment every season.

But this is hard country. Unlike the deep alluvial silts of the Canterbury Plains, much of this region is barely more than rock. In fact, 20 years ago much of it was desert-like, with sparsely stocked sheep stations making use of what little scrub grew.

But in the last two decades that’s changed dramatically. With irrigation, what were once arid, unproductive areas are more productive farmland capable of supporting herds of milking cows and increasing stock numbers on sheep and beef stations.

Consequently huge numbers of monstrous centre-pivot irrigators have sprung up across the area (the longest runs to 1228 metres).

“Our business has changed dramatically since I moved here in 1999,” O’Neill says.

“They might have water on tap but these farmers still require the ground to support some sort of pasture. Often we get the job of transforming what is effectively bare rock into some sort of seedbed – and that’s tough on machines.”

The process of breaking in new ground is thirsty, time-consuming work. First, the tussock grass and scrub is mulched and the re-growth sprayed off. Then, depending on the make-up of the land, either a disc or plough is used to make the first pass.

Much of the time a heavily modified Sumo Trio does the hard work. Instead of conventional winged sub-soiler legs, ripper tines with digger bucket teeth are used to carve channels through the ground without bringing too many stones to the surface. Behind that the mounting of the two rows of discs has been altered so each disc is individually sprung to contour better and carry more fine soil with them. Next a 6m hydraulic levelling bar is pulled over the surface to even out any humps and hollows. Then comes the drill and often a final pass from a heavy vibrating roller to pulverise any remaining rocks and punch them down into the dirt.

This rough work requires a particularly robust seeding set-up.

Time inevitably takes its toll and they were starting to shear bolts in the parallel linkages that carry the coulters. So in 2010 they ordered a fresh one and traded the old one in.

“But pretty quickly we realised we couldn’t cover the workload – virtually every farmer in the region had moved over to us for their reseeds and cereal drilling because the Allen was the only drill that could do the job reliably.”

So the team at Ashburton were tasked with converting the old rig to a min-till cultivator drill – effectively a heavy-duty version of the Vaderstad Rapid – well-suited to getting cereal crops established. It’s still going strong today, as is its replacement.

But with more and more land going under centre-pivots, demand for a robust, reliable means of getting pasture established continued to grow and so three years ago O’Neill ordered his third Allen drill – this time a 5m machine.

It’s proved a firm favourite with operator Ben Scott and, pulled with a Fendt 927, it now handles the lion’s share of the drilling workload – some 3000ha/year.

“My life is made easy by the Allen drill. Being that little bit wider I can trundle on at a steady pace – 8-12kph – with the tractor barely going above 1500rpm and still cover a decent lump of ground each day.

“But it’s the clever design that makes it such a breeze to use. Having constant oil flow to the wings with the fold rams plumbed into the fan circuit and cushioned by gas accumulators means it will nearly always get the seed in the ground, no matter how hard.

“It’s a real driver’s machine. Calibration is a dead simple with the RDS box and often I’m working on my own right out in the back country so having the Hiab crane is a godsend.”

As regards wearing parts, the twin-disc coulters will stretch to 2500ha in the region’s unforgiving conditions while the wavy opening discs will handle about 1000ha before they need changing.

And it’s a similar story for the rubber sausages that provide damping of these leading discs.

Changing them is a tricky task because each pair weigh over 75kg and by their nature they are unbalanced with the majority of their weight at the rear. Not being strangers to the job, the workshop team of Jason Waters and Craig Lintern have built their own support rig to make changeovers a simpler task.

“Ultimately we’re getting a huge amount more work out of our Allen drills than I believe is possible with any other seeder,” O’Neill says.

“We’re asking a lot of them but they’re built heavy enough that they will go into the ground and stay in the ground. That way we can guarantee reliable crop establishment and our customers keep coming back – that’s the crucial thing you’ve got to get right in the contracting game.”

Dave O’Neill started out in 2002 with a Duncan Enviro drill doing 1200-1500ha of direct reseeds each season but after three years the stony conditions had completely worn it out.

“Next I tried a Gaspardo direct drill but it fell to pieces in that first season. I’d heard good things about Allen drills and so we had one on demo. I really liked the concept and particularly the heavy build but those early rigid-frame HDs were no good for contouring.

“I could see that the restriction came in having the opening discs way out ahead of the coulters so I asked if it was possible to bring them closer together, move the transport wheels to the rear and split the frame in two.

“We drew the basic design in the dust and that’s pretty much how our first 4m Allen drill shaped up. Calling them ‘custom’ drills is certainly true – you can ask for pretty much anything and they’ll make it work.”

In reality, that was the first-ever Allen CD drill built. Over the years it had certain mods to cope with the extreme North Otago and MacKenzie Country conditions.

Renowned for its ability to snap a pocket knife, the stony soil could bend discs and meant bearing replacement became a regular task. That’s when the Allen team introduced its rubber-sausage toolbar mounting, instantly sorting those issues. With the upgrades in place, that first drill did five years before O’Neill decided it was time for a freshen up.

“The Allen was amazingly robust compared to anything we’d had before. It’s pretty extreme, what we’re asking it to do.

“In the really stony ground we’re not expecting it to split rocks in half but it has to be able to ride up over the big ones and push back down between the smaller ones.”


David O’Neill Contracting, Omarama, North Otago
Work undertaken:
• Silage – 2500-3000ha/year
• Baling – 4000-4500 four-string square bales/year plus 8000-10,000 round bales/year
• Fertiliser – 18,000-20,000ha/year
• Cultivations – 1000-2000ha/year
• Drilling – 4000-4500ha/year
• Farmed area 530ha – barley, rye and triticale
• Machinery Tractors – Fendt 3 x 818s, 824, 924 and 2 x 927s, MF 5465, 6465, 6480, 7615, 7618, 2 x 7622 and 7726
• Loaders – 2 x Merlo P34.7, MF TH7308 and JCB 434-S shovel
• Trucks – 9 x Scanias and 1 x MB
• Combine – Case IH AF6088 with 9m (30ft) MacDon draper header
• Forager – Claas Jaguar 950
• Drills – Allen Custom CD5000 and 2 x CD 4000
• Staff – David and Prue O’Neill plus six full-timers and up to 20 others at peak times