3 July 1998

Right combine settings can keep it clean

Cleaner crops and more

efficient combines mean

growers can produce a clean

grain sample before the crop

reaches the store. But the

combine must be set

correctly and thropughput

adjusted accordingly.

Mike Williams explains

MANY combines do more than just harvest grain – they handle all the cleaning as well.

A growing number of farmers are managing without a separate grain cleaner in the barn. One of them is Richard Wrinch who has farmed without a grain cleaner since he returned from college in 1971 to help his father run the family farm at Shotley, near Ipswich, Suffolk.

Mr Wrinch grows 648ha (1600 acres) of combinable crops, including some contract farming, with milling and feed wheats plus malting barley the key crops. He brings in a mobile seed dressing service for grain kept as seed, but the rest is sold without further cleaning.

"We have considered putting in a grain cleaner, but have never done so because we manage well without," explains Mr Wrinch. "A modern combine harvester will do the job perfectly well if it is set up properly and we are careful about the way we adjust the combine.

"But being careful does not mean we lose out on output. We did the whole of our acreage last year with one Claas Lexion 460 combine and the output was impressive, particularly in wheat."

As well as taking care about setting up the combine, Mr Wrinch is also careful about weed control.

Unless there is a change in the marketing requirements for cereals, he says there is little incentive to invest in cleaning equipment and will continue to do the job on the combine.

Mr Wrinch is far from being the only cereal grower to rely on the combine to clean the sample. According to John Bailey, Essex-based ADAS machinery specialist, the big acreage arable farms are setting the pace. "We have almost reached the stage when it would be a surprise to hear from a farmer who was planning to put in a new grain cleaner," he says. "One of the reasons is that crops are so much cleaner than they used to be because chemical weed control is so effective these days.

"The other factor is the big improvement in cleaning efficiency on modern combines, which means you can set them up to produce a marketable sample without additional cleaning on the farm."

Expecting the combine to do an efficient cleaning job may mean some loss of throughput, Mr Bailey admits, but most cereal growers have more harvesting capacity than they actually need and a slight reduction in the work rate should not be a problem.

"There are 300 hours available for harvesting in the eastern counties, but most of the combines do 200 hours or less, which means they could afford a 10% loss of work rate in a few fields to get extra cleaning capacity when it is needed."

Robin Thompstone, Massey Ferguson combine specialist, believes most cereal growers are aiming to get the material other than grain (MOG) content low enough to avoid a price penalty when they sell, but cleaning beyond that point simply reduces the saleable weight.

"These days combines are quite capable of producing a marketable sample without further cleaning, and crops are generally so clean that there should be no significant reduction in work rates in about 90% of fields."

Much of the extra cleaning capacity is due to the improvement in fan performance, Claas combine specialist Laurence Rooke points out. Makers have switched from the old paddle fans to turbines, which are much more efficient and maintain a constant blast. The two-stage sieving process also helps to give a cleaner sample.

"Under most conditions a modern combine will produce a sample which is clean enough to meet the requirements for intervention," says Mr Rooke. "But if you want grain which looks as if it has been through a dresser it will mean tightening the sieves so much that there will be a significant reduction in throughput. This will probably reduce work rate by 10% and if that is not acceptable cleaning should be done separately."

But not everyone is happy to trust the combine to do the cleaning, and grain cleaners are regularly used on arable farms managed by Sentry Farming.

"Our policy is to enhance the value of our products as far as possible, and that means a lot of our grain goes through a grain cleaner," says chairman, David Richardson. &#42

A well set combine can produce a clean grain sample before the crop even leaves the field, says Suffolk farmer Richard Wrinch (inset). But for a sample as clean as one from a dresser work rate may need cutting by up to 10%, warn machinery experts.

COMBINE CLEANING

&#8226 Combine can replace cleaner.

&#8226 Ensure weed conytrol and combine settings are spot on.

&#8226 Tighten sieves and cut throughput 10% for dressed grain effect.