Based just minutes from the seaside town of Rosslare, Co Wexford, Nicky Keane is a tillage farmer, growing in the region of 900 acres of combinable spring and winter crops.

While winter wheat is the predominant crop, a strong mix of other cereals, beans and OSR is also grown, which leaves for a steady harvest season – generally running from July to September.










Last year, the farm’s combine was upgraded to a new John Deere T660i, the third consecutive T660i purchased since 2012. Since then, Nicky has bought his combines in partnership with his brother-in-law. Not only has such a move been a success from the point of view of reducing the cost of ownership for both parties, but it made the option of opting for a slightly larger output combine feasible.

The unloading auger has a capacity of 125l/s.

The combine is fitted with 800/65 R32 front and 540/65 R30 rear tyres.


Combined, Nicky and his brother in law Geoff Barry, harvest 1,400 acres. This tends to be at the higher end of the scale for the work done with one straw walker machine in Ireland, Nicky and Geoff now aim to keep the combine changed after four seasons – or at a point that they consider to make the most financial sense, based on ownerships costs.

Today, over 90% of Nicky’s crops are established using min-till and direct drill practises, a transition that first started back in 2008. Such practises have led to reductions in fuel usage and the labour required to do autumn and spring sowing. Yield-mapping with the combine now too since 2018, Nicky has taken the progressive approach and trialled variable rate sowing based on yield map data. This year, lower yielding areas within the 40ac trial plot received 76kg/acre of seed, while the higher yielding areas received 63.5kg/acre of seed. Within which, Nicky has sown 1,270kg less seed and so far has witnessed a more even crop.

With the introduction of the straw incorporation scheme, Nicky chopped over 400 acres of straw last year, double that of the 2021 harvest. He expects this year’s acreage to finish up somewhere similar. With that in mind, he doesn’t envisage moving away from a walker machine to a rotary machine any time in the near future. Aside from being happy with the output of the T660i, he feels the additional buying price of a rotary equivalent cannot be justified for his farm.

Given that Nicky operates the combine, we caught up with himto find out more about the machine and his experiences with it so far, as he was harvesting winter wheat yielding between 4.0t and 4.2t/ac.

The optional folding unloading auger leaves entering and exiting tight entrances easier.

Nicky is fond of the cab and control layout.

Why John Deere?

Traditionally, Nicky and his father would have run two older combines. With acreage increasing in the early 2010s, he felt opting for one new machine with greater output was the way forward.

“I had a New Holland TX66 prior to the first T660i, which I was very fond of. But I felt it was between Claas and John Deere when buying new, based on dealer proximity and backup. I demoed a Claas Lexion 670 and John Deere T660i. Both were great machines, but I felt the cab and operating system of the John Deere had the edge. Three machines later and we’re still running a T660i John Deere.”

Given that Nicky was operating a fleet of John Deere tractors and was situated closer to TFM in Enniscorthy compounded the decision.

The standard choping unit comprises 52 double-side knives mounted across six rows.

The HillMaster feature uses hydraulics to level the entire combine on side slopes.

Header and tech

When buying the second T660i in 2018, Nicky decided to opt for the HillMaster side slope system and, more recently, on his current machine which was delivered in 2022, he opted for the X series variable header, in addition to the HillMaster system. For peace of mind, Nicky opted for the 4wd kit on the three T660i models to date.

Having previously run fixed type R series headers, the 7.6m (25ft) 725X series header on his current machine benefits from a table that varies in length from 490mm to 1,200mm. This allows for reduced losses in crops such as OSR or in laid crops. Nicky is well impressed by the headers ground following abilities and crop flow and presentation as it enters the 1.67m feeder house. The only downside being the additional weight over the standard R series header.

The HillMaster system uses hydraulics to level the whole combine on slopes up to 15%. When combined with the factory fitted sidehill kit, another 7% is added, taking the total slope compensation to 22%. Although Nicky isn’t farming on the hilliest of land, he finds it a worthwhile addition to minimise losses and improve comfort.

Other optional features and technology on board includes yield mapping, grain moisture sensing, AutoTrac, folding unloading auger and the on-board air compressor.

All of Nicky's T660i combines have been fitted with 4WD.

Threshing and separation

The T660i uses a multi drum separation system, with a total separation area of 4m2. In theory, this translates to a throughput of 55t/hr.

Once crop enters the feeder-house, it is accelerated to a claimed figure of 3.6m/s before reaching the threshing drum. The header drive uses a 900Nm slip clutch to keep crop flowing in the toughest of conditions. An 80hp mechanical reverser is designed to clear any plugs directly from the cab.

Deere use a 660mm threshing drum fitted, with 10 rasp bars and a 124-degree concave, meaning that four rasp bars are engaged with the concave at all times for optimum crop compression.

Once crop leaves the threshing concave, the gap widens between the drum of the 500mm overshot beater and the combine housing. It’s here the separation process starts as crop passes over the top of the cylinder instead of under it, a key feature in preserving straw quality according to Deere.

As the crop exits the Tangential Plus separator concave, it is pulled onto the walkers by the rear discharge beater. Secondary separation takes place here as the drum has its own mini concave.

The walkers operate at a speed of 150rpm with a 150mm throw. They are designed with high steps to keep the crop on the walkers for longer. Nicky is impressed by the layout and effectiveness of the threshing/separation system, noting that has always proved easy set for low losses.

Sectional concaves leave changing between crop types easy. When more intensive threshing is required, a booster bar can be manually engaged as an alternative to de-awning plates.

Nicky Keane, Rosslare, Co Wexford.

Grain cleaning and chopping

The T660i has a total cleaning area of 6.3m2, aided by a large fan capable of producing 740m3/min of air flow. Returns are delivered back to the cylinder and distributed over its full width. During the cleaning process, the crop cascades 41cm down on to two ventilated steps, which help to pre-clean any chaff.

Nicky’s machine is equipped with the standard chopper option, which sees a total of 52 double-sided knives mounted across six rows. In terms of fuel consumption, in a typical crop of winter wheat Nicky tends to average in the region of 20.4l/ha chopping. When laying straw, fuel consumption reduces by about 2-3l/ha, not as much as he initially expected. For road transport, the spreader unit is manually folded.

The T660i is equipped with a 25ft 725X variable table header.


Now well into his second season with over 520 engine and 360 drum hours clocked, Nicky remains happy with the T660i. While the extra 68hp of the flagship T670i would be welcomed during the brief period of unloading and chopping, he feels the additional buying price outweighs the power benefit.

“It’s a combination of performance, reliability, usability, comfort and a relatively low running cost that has been the reason for not moving away from the T660i since 2012. Today we got through 59 acres of winter wheat, which averaged just over the 4t/ac mark between 9:30am and 7:30pm.

“The 25ft X series header has been a good step up from the R series I previously ran. Like the HillMaster feature, I’d find it hard to move away from it now. I went for the optional longer. folding unloading auger. Given that I have to turn in off a lot of small roads, tail swing is less of an issue as the auger is tucked in tightly to the rear of the machine.

“The only thing I would point out is that a lot of dust and debris can gather up around the engine and exhaust after treatment system. It’s important to constantly keep an eye on this and keep the machine blown down daily. My old TX66 had an air purge system that would purge the engine bay with air every so often and stop any build up. I think a feature like this would be very useful.

“The backup from TFM has been exceptional, it’s a great confidence booster knowing that if I’m broken down that they will have a spare header or combine for me. Again, this was one of the main factors for going with John Deere in 2012.”