J A J Sawbridge and Sons: tracks or tyres?: Choose your boots

REPORT: Tracks or wheels? For one Buckinghamshire farm, both may turn out to be the answer. Purchasing a John Deere 8RX410 last season has brought unexpected benefits, but its wheeled ‘brother’ also has a place in a fleet which is being transformed to suit the demands of an evolving enterprise.

The Sawbridges have been farming in Warwickshire, Northamptonshire and Buckinghamshire since the 1730s, but it’s safe to say that it is now a very modern agricultural business. As Milton Keynes continues to expand, William Sawbridge farms 1,575ha of arable and grass on owned land, FBT and contract farming agreements at Lodge Farm, Castlethorpe – just six miles from the town centre.

Meanwhile brother Philip Sawbridge has moved away from farming to run a business park alongside it. The future of Milton Keynes is development and it is getting ever closer, so we may look for other land to crop and move away from this site in the long term, but we will always farm,” William says.

But it in order to do that farming efficiently, J A J Sawbridge and Sons has been fettling its machinery fleet over the years.. “It’s significant even down to getting and retaining good staff, which is key to the business,” comments William. “Father always had Fords, but after a season contract combining in the USA in my youth, I was convinced we should switch to John Deere.” Starting with a 4450 pulling a five-furrow Dowdeswell plough, the green fleet began to take over by 1985. More recently, after taking on combining at another farm meant that more harvesting capacity was needed, a pair of second hand Deere combines were added, replacing a Claas Lexion. A 4040i selfpropelled sprayer makes the ‘set’ complete.

Dividing the business four years ago shrunk the fleet somewhat, and led to a wide-ranging rethink of equipment choices.

“Like everyone else, we were suffering from high fertiliser and diesel costs, compounded by two bad autumns. We’ve focused on growing all milling wheat and seed for Warburtons, working with Agrii and the CMG,” he explains. “Everything is geared towards the premium; we know our costs of production and target three to four tonnes per acre.” After being in countryside stewardship for 20 years – including a very public brush with the RPA where the farm was wrongly penalised for alleged discrepancies in compliance – he is now navigating the SFI.

“We had two mid-tier schemes at Castlethorpe for AB8, AB9 and AB18, which took out 38ha. Going into SFI in 2024 this will increase, using AHL1 (Pollen and nectar mix), and AHL2 (winter bird food), while we’re also looking at companion crop and no insecticide options. At £739/ha for AHL1 and £853/ha for AHL2, it’s an obvious move.”

Oilseed rape and beans have already come out of the rotation due to their poor margins; William comments that the choice between wheat and SFI /mid-tier options will be closely monitored for its profit potential in the future.

“We’ll sit down post-harvest and look at the wheat price; if it’s £260-300/tonne we can focus on wheat, but SFI is equivalent to second or third wheat and acts as a break crop anyway, so it will definitely be part of our plan going forward.”

The aim is to move to no-till, but on the notorious Hanslope clay to the north of Lodge Farm, non-inversion tillage and direct drilling has allowed black grass to take hold, so the plough remains an important part of the armoury.

Turning to tracks

Two John Deere 8370R wheeled tractors were replaced with the tracked 8RX410 in 2023, aiming to get more from one cultivations machine.

“Previously, I drove one of the tractors and my son George the other one, pulling a 5.0m Kuhn Performer and 10m Simba Cultipress. But when he went off to university, I looked at increasing capacity to do the work with one tractor. I was initially interested in a Quadtrac, but my enquiry wasn’t followed up.” Discussions with John Deere dealer Farol followed, with the choice made more difficult due to tractor supply issues post-Covid.

“I also considered a Deere 9620 articulated tractor, but Farol reckoned that the 8RX410 would do a better job,” he recalls.

The 8RX has 443hp max John Deere engine, driving through the company’s EAutoPowr stepless transmission, with electric start designed to deliver immediate power and torque to handle some of the more demanding cultivation kit. However, in common with the rest of the country last autumn, no amount of tractor power was much help. With 200 hectares left to drill, work ground to a halt. “We’d been using the 8RX with a Grange toolbar in front of a Kuhn Optimer and looking to drill with a 12m Horsch Sprinter but it was to no avail. It was just too wet and we had 500 acres left undrilled,” says William. “As we planned to direct drill, the aim was to just lift and tickle the top, but with hindsight we’d have been better to use the Performer and go a bit deeper; we got crop in on the ploughed land.”

The new purchase showed its mettle in the spring, where fields that had been sprayed off over the winter stayed wet.
“We were able to use the 8RX to get on with a 6.0m set of Cousins tines to get air into the soil, before going in with the Optimer and power harrow ahead of the drill.”

He comments that they were amazed at how well the tracklayer – which weighs in at 19.5 tonnes – travelled. The four-track design gives 4.57m of ground contact area and exerts 36kPa fully ballasted.

“It simply sat on top, we couldn’t have done it with a wheeled tractor. We’ve used it for drilling spring wheat and patched up headlands where we did get crop in last autumn – the tyres on the Sprinter can do a lot of damage and you do need an operator who understands the impact on the soil.” Some of the land which went into SFI in spring 2024 was originally destined for AD maize, but the land remained waterlogged way beyond the maize planting window; the 8RX was nimble enough to get on with establishing the AHL1/AHL2 in June.

Tyres still have a place

Wheeled tractor choice also got an upgrade. “We’ve got a great relationship with Farol, and as our Deere 7310 was struggling with the seven furrow Kverneland plough and other big implements, they suggested swapping it for a 2021 plate 8R410 on 900 tyres; it didn’t turn a wheel before this spring but will be part of the future plans.”

The two tractors can work together in the autumn; they are supported by a 6215R and 6250R which also come in for grain carting, topping etc. Operationally, they are very similar tractors, drivers Tom Smith and Henry Sawbridge confirm.

“The EAutoPowr transmission can be driven in manual or full auto, setting up maximum and minimum gears. It takes a bit of getting used to but is then straightforward,” comments Tom.

The ability of the CVT to work with the engine has also helped cut fuel consumption, he reckons. “It is never working hard – the tractor just sits at 1,500 rpm on the power harrow,” he says.

The versatility of the 8RX shown this spring means that it can be interchanged with the wheeled tractor to suit the conditions and Tom comments that it’s easy to configure the hydraulics and store profiles for the implements so they can be swapped between the two.

Cab comfort is praised; the tilting undercarriage and suspended mid-rear roller bogie mounting to the rear work with the cab suspension to smooth out the usual tracklayer ‘rock and roll’. The 8RX offers another benefit on the increasingly busy Buckinghamshire roads.

“On the wheeled tractor, you do need to keep an eye on kerbs going through the villages as the 900 tyres sit outside the mudguards; the 8RX is very compact for its power,” comments Henry.

Tech benefits

The team at Sawbridges are getting to grips with John Deere’s latest technology on the tractors, but William has already seen the benefits of telematics on the S685i and S690i combines.

“It’s so useful to have all the data on my phone, to know where the combines are and to be able to look at the yield maps straight away so that we can address any problems. It’s also helped with management decisions – I can see exactly how the trailers are doing, and its enabled us to go down from six trailers to four, freeing up a tractor at harvest.”

A review of drill choices will also simplify establishment. “I swapped a 6.0m Sprinter, 6.0m Rapid and 6.0m Kverneland Evo for the 12m Sprinter; a 6.0m Kuhn Megant was part grant-funded and is useful for spring wheat, while the Sprinter will do the SFI crops.”

In autumn, the Sprinter can comfortably cover 100ha per day, with the Megant also coming in for the headlands. Having the flexibility of wheeled and tracked machines at 410hp means that plans for this autumn were put in place early.

“We’ll get the SFI cover off quickly and cultivate as soon as possible so that we don’t get caught out by a difficult autumn. On maize ground we’ll have the capacity to get on and plough while it’s dry with a more powerful wheeled tractor. A more versatile fleet should make all the difference,” he says.

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