Norfolk's broad acres may be commonly regarded as 'flat' – as the playwright Noel Coward famously described the county – but there is a keen demand for specialised 'hill' combine harvesters.

And agricultural engineers Ben Burgess & Co, based in Norwich, sells two or three John Deere HillMaster combines each season to cereal growers with more rolling slopes than level fields.

In Noel Coward's 1930 comedy, Private Lives, one of his characters says: 'Very flat, Norfolk' but clearly had not tried to harvest fields of wheat and barley in parts of North Norfolk or around Bury St Edmunds.

David Fairman, group sales and export manager, said that for farmers with more rolling land, the HillMaster range can easily pay for itself in cleaner grain samples and reduced losses.

There was a further advantage when machines were sold because there was strong demand from other parts of the country and in Europe.

'Of about a dozen combines we sell each year, we sell two or three HillMasters. When you get around Bury St Edmunds and the North Norfolk coast and other places there are some significant hills,' he said.

'There's a surprising amount of farmers running them where 70pc of the land is hilly and for the 800 acre to 1,000-acre farm, we sell a surprising number of these range of machines with a 20ft to 22ft header.'

'Although most manufacturers have some sort of Hillside option, John Deere is the best, but I would say that, because it levels the whole combine rather than the sieves. If you've got slopes, you'll notice the difference,' said Mr Fairman.

Ben Turner junior, who is based at the firm's Norwich headquarters, said a farmer on the Cambridgeshire borders asked for a quote on a 'level' combine and a HillMaster. He has opted for the HillMaster, with 30ft header, because of its flexibility.

'It can work on the level but comes into its own on the hills, slopes and rolling ground,' he said.

A key difference was that the whole combine could work level when on sloping ground, so that maximum performance and harvesting efficiency could be achieved, he added.

'These's nothing active like the HillMaster system which changes to keep the entire combine to keep it on the level.

'It really does have a bit of a following,' said Mr Turner, who is the great grandson of the firm's founder, the late Ben Burgess.

The HillMaster range offers combine header widths from 20ft to 22ft through to 35ft for the more powerful 500hp models

And there is a further advantage when moving out of the harvest field, said Mr Turner.

'If you've got a number of gateways and the combine head doesn't quite fit through, you can manually adjust the tilt of the combine and header. Instead of losing time removing the header, it can be tilted to about 20 degrees. One end of the header can go through the gate and the rest over the hedge! You can get a 25ft or 30ft header through a 20ft wide gateway,' he added.

Since he advertised the T550i HillMaster combine in the EDP's Farm & Country last week at £132,487, Mr Turner said that he has had his leg pulled about selling 'hill' combines in Norfolk. 'But there really is a demand for these machines,' he added.