19 September 1998


Its never been more vital to know exactly how much your crops have yielded. Geoff Ashcroft outlines the experience of three farmers using different grain weighing systems.

AT Elkington Lodge, Welford, Northants, grower John Cobbold relies on a two-axle weighbridge to monitor what comes in to, and out of, the grain store.

The 202ha (500-acre) unit grows a combination of oilseed rape, first wheats, winter barley and spring beans, with an additional 140ha (345 acres) of contract combining carried out for neighbouring farms.

"We first started weighing about 10 years ago, but initially for bulk fertiliser. We needed to know exactly what was coming in and, of course, what was going on to each field," explains Mr Cobbold.

Buying fertiliser in bulk gives him a saving of about £8/t – which adds up to an annual saving of about £700, which is easily offset against the cost of the weighbridge. Bought second-hand at a farm sale for about £5,000 – including installation – the H&D tri-axle weighbridge allows split weighing of loads. A tractor/trailer combination requires the tractor to be weighed first, then driven forward to place the trailer wheels on the weighbridge.

Accuracy, says Mr Cobbold, is within 0.5%. "We now weigh every load off the combine and enter the information in a book alongside the weighbridges computer. Its a sort of double-check system, so we can keep track of how different varieties from different fields have yielded."

Describing himself as computer literate, John Cobbold admits that the weighbridge computer is too complicated for him – though he has got the most sophisticated version offered by H&D.

"You need to be diligent with its operation. It is easy to input the wrong information on fields or varieties, which will make all your results inaccurate. If you can avoid inputting the errors to begin with, then the information you get out of the weighbridge is extremely valuable as a management tool. H&D does make a simpler control box which would have been quite sufficient for me."

"Compared to a new weighbridge, our second-hand weighbridge is a considerable bargain. And although it wont make you any more money, it does help you to make informed management decisions. We couldnt do without it now."

Oxfordshire farmer David Parker prefers an on-board weigher on the combine, simply because its easier to justify than an all-singing, all-dancing weighbridge installation. From Model Farm, Shirburn near Watlington, Mr Parker farms about 364ha (900 acres) of which 230ha (570 acres) are arable. Harvesting is down to a Claas Lexion 430 which uses the firms own Quantimeter system.

"Weve been gathering yield information off the combine for a few years now, and until I bought the Lexion, it was a system which was accurate to within 1%," explains Mr Parker.

"The new Quantimeter system – compared to the Claydon Yield-o-Meter we used to have – falls somewhat short in accuracy. Its more of a rough guide, being within 5%.

"Its more frustrating when youve had accurate yield information and then you take a few steps backwards with a system which does not offer quite the accuracy youve been used to. It also means I cannot forecast properly, or plan storage because I can only estimate what the yields are going to be. This year, our barley turned out to be a much bigger heap than the Quantimeter said it would be.

Also using a combine-based weighing system is Suffolk grower John Price. His Claas Mega 204 is equipped with a Claydon Yield-o-Meter which helps him to make informed management decisions – often during the busy harvest period when clear, lateral thinking can sometimes fade into insignificance.

"It helps to know what to expect off each field so we can make best use of our storage facilities," says Mr Price, who has been using a combine-based weighing system for the last 18 years.

Based at Rylands Farm, Steeple Bumpstead near Haverhill, he grows 283ha (700 acres) of combinable crops, of which 178ha are wheat, 56ha are winter barley and 48ha is oilseed rape. Because he carries out his own nitrogen and fungicide trials work with small areas of new cereal varieties sown in blocks among the main crops, he finds the Claydon Yield-o-Meter an accurate way of assessing yield potential.

And by carrying out trials work and gathering the results via the Claydon Yield-o-Meter, Mr Price has also been able to cut seed rates by up to 0.25cwt/acre.

"Reducing seed rates has had little effect on yields on our farm, and it means weve shaved a considerable amount of money from our seed bills.

"The Yield-o-Meter is very accurate; on 1,000t of grain, we were only 5t out last year. Being able to assess yields straight from the combine has become an essential aspect of our business – its a management tool."

With the yield information, Mr Price is also able to make accurate cash flow forecasts for the coming season, which also helps when making buying decisions for machinery, fertilisers and other inputs.

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