John Deere’s entry into the 800hp+ self propelled forage harvester market has seen its newly unveiled 7950i model debut at UK on-farm demonstrations.

The 812hp machine, powered by a Cummins 19-litre power plant has seen chassis, drive chain, and forage processing equipment beefed up to accommodate the extra hike in power.

UK field demos so far suggest up to 300t of maize an hour harvested at 18mm chop length using a Kemper 10-row header.

The 7950i – which comes in 2wd or 4wd formats with or without the company’s HarvestLab technology denoted by the “i” suffix – is aimed at top end contractors. “The UK market for foragers is roughly 150 units/year with just 3-4% being machines of this output,” says Richard Halsall, John Deere’s product manager.

On the “i” model, consistent chop length is achieved using the HarvestLab NIR dry matter sensors on the spout to adjust the chop length transmission on the move to get consistent forage quality.

John Deere’s 7950i model has made its debut at UK farm demonstrations.

Stronger rollers and bearings on feed rollers deliver material to a 40-blade cutting head capable of 6-26mm chop length while 48- and 56-blade options are also available depending on application. The on-board reverse sharpening facility helps maintain a sharp edge and reduces risk of metal fragments affecting the demagnetised feed roller housing the machine’s metal detector.

Cutter blades are accessed easily for maintenance and angled to improve forage flow into the processing equipment housed in the longer, wider machine chassis.

Added power has seen drive to the kernel processing unit also improved now using a multi-ribbed power band belt.

Other changes up front see a stronger final drive unit fitted and 23% increase in header lift capacity helping accommodate 10- and 12-row (9m-wide) Kemper headers for maize crops.

The huge header unit accommodated by the 7950i has seen John Deere developed an innovative carriage wheel sub-frame to support the weight during transport. This reduces on-road ‘bounce’ and the need for rear-end ballast.

Running costs for contractors remains of paramount importance. A new engine and speed management system for the 7950i includes Road Mode keeping revs between 1250-2100rpm offering better torque when needed and saving fuel. Field Modes also adjust engine speed to conditions, such as lower on headlands when turning, offering a 5% saving in fuel, claims John Deere.

With 1000-litre fuel storage on board, tests suggest usage can be as low as 0.5 litres/t forage processed although UK conditions, with smaller field runs among physical limitations, likely to pull fuel usage up.

The step up in power and output requires significant investment with the guide price for the 7950i starting at £269,502 for a 2wd model rising to £317,281 for the 4wd 7950i. But that should be money invested well, says John Deere.

The 7950i is not a mass market machine, admits Mr Halsall. For those contractors demanding high throughput – whether grass, maize or biofuel crop – the 7950i will deliver efficiencies in harvesting output based on John Deere’s reputation for build quality and on-farm back up.