17 May 2002

Measuring kit takes guess out of grain losses

By Andy Moore

UNSURE just how much grain is being lost out the back of a combine harvester?

Traditional methods of burying the head in the swath are unpredictable to say the least.

Combine hire and supply company APH now offers a grain loss measuring kit which could help to evaluate the degree of losses and answer the question whether those losses are acceptable or not.

Called the Maximiser, the kit comprises a collection tray, Winnowing canister, a measuring cylinder and a set of conversion charts.

In operation, the kits 2.10m x 30cm tray and mesh is thrown underneath the combine while it is in motion and into the path of the exiting straw swath.

The tray is designed to catch a 30cm (1ft) width of lost grain and chaff out the back of the combine. Once the combine has passed over the tray, its mesh is removed to separate straw and the contents are poured into the Winnowing canister.

Powered by a 12v rechargeable battery, a fan in the canister blows away chaff and straw. The remaining clean sample of wheat or barley is then poured into a measuring cylinder.

Units on the side of the vessel – 24 to 1000 for example – denote how much grain is in the cylinder and hence lost out the back of the combine.

"The measured amount of grain is cross-referenced to the chart which tells how much grain is being lost for a given header size and crop yield," says Steve Allen of APH. "If there are 600 grains in the cylinder, the chart shows grain loss is 1% for a winter wheat crop yielding 4t/acre."

The key behind the chart is the "lost grains/sq ft and kg/acre", which are calculated from a formula.

"If just 1% of grain from a 4t/acre crop is lost out the back of a machine with a 24ft header, the grower could be losing £2.40/acre," he adds "This adds up to £2400 lost over 1000 acres based on grain worth £60/t."

Conversely, Mr Allen says that if grain loss is very low, the driver will know the combine is being operated at under capacity.

Once an accurate grain loss percentage is attained, the combines own in-cab loss monitor can be set up to work from the chart and calibrated more precisely, he adds.

"With an acceptable percentage loss entered into the in-cab computer, the driver can operate the combine more efficiently. Rather than scrabbling around in swathes trying to guess how much grain is being lost, the driver just needs to perform the test a couple of times a day."

Price of the kit is £495. &#42

Steve Allen:"The Mamixiser takes the guesswork out of trying to ascertain how much grain is being lost."