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15 Oct 2020

Finding the harvest balance

As featured in Arable Farming Magazine

Finding the harvest balance

by Arable Farming

The Bushel Plus loss monitoring system is a relatively new product to the market, but for one Oxfordshire farm, it has helped to increase the speed at which valuable crops have been harvested for two seasons. Alex Heath finds out more.

For Tim Chamberlain of Crowmarsh Battle Farms, ensuring crops are harvested at the optimum time, while maximising the amount of grain getting into the tank, is a priority.

With a mixture of owned, tenanted and contract farmed land, the 1,416-hectare Oxfordshire unit places great emphasis on maximising yield from every field.

But with a varied crop rotation, including wheat for both milling and animal feed, barley destined for malting, oilseed rape, beans and poppies, a balance has to be struck between combine forward speed and accounting for losses.

For the past two seasons the farm has used the Bushel Plus combine calibration system, designed and manufactured in Canada, and has a price tag of £1,800.

The rationale behind adopting the system was the need for a safe way of acquiring repeatable results that can be input into the combines computer to adjust the

sensitivity of the onboard loss monitor. The combine in question is a Massey Ferguson Ideal 9 ParaLevel complete with 10.6-metre header, bought two years ago, replacing a brace of Delta machines from the same manufacturer.


Mr Chamberlain says the farm would traditionally carry out tray tests to establish a loss percentage. However, this method is neither accurate nor repeatable

and also means having someone in close proximity to the combine, with associated dust and heat issues. Consequently, the Bushel Plus method had immediate appeal, he says.

Traditional tray tests mean having an operator, typically my 68-year-old father, in the thick of the dust stream coming off the combine. If someone else is

carrying it out, it is a subjective test, as is counting the grains under the hand.

Coupled to this, we would not know if the grains had been shed previously or were a result of the combine. Anything to make the task simple and accurate will get used and ultimately makes harvest more efficient.

To this end, the Bushel Plus system, which comprise a carrier unit, drop tray and air separator has made its mark on the farm.

We might only drop the tray once a day if we are in one field with good conditions. Conversely, if the weather and temperature are changing throughout the day, we move fields or change varieties, it may get dropped more than a dozen times, but I know once it has been done, we can fine-tune the combine depending on what we are trying to achieve, says Mr Chamberlain.

Remote control

The main part of the system is secured underneath the combine with heavy duty magnets. The carrier unit houses an electromagnet, dropping the tray when

the remote control, which is kept in the combine cab or with a trailer driver, tells it to do so.

The electromagnet only drops the tray when it is powered up, meaning it will not drop if the battery runs out. The battery is good for more than 100 drops.

The carrier unit can be placed nearly anywhere to pinpoint losses from specific areas of the machine. Mr Chamberlain has placed his underneath the feeder

housing so, when the tray is dropped, the whole of the combine passes over it, ensuring a full picture is gathered.

This position also allows for easy access to reinstall the tray.

We did have it placed on the back axle, targeting losses coming over the back of the sieves, but when passing over large swaths of straw on the headland, there was not enough clearance, Mr Chamberlain says.

The tray is contained within the carrier unit, stopping any errant grains getting into it when not in use. The unit used by Mr Chamberlain is the standard 1m

wide model, which comes with two trays, the standard 0.25sq.m tray, used for most cereal crops, and a narrower 0.125sq.m tray, designed for use in oilseed crops, where the taller and wider spaced stubbles make it more suitable, slotting in between the crop stubble and dropping to the ground.

The second part of the system is the air separator, a cylindrical device with a fan in the bottom.

The contents of the trays are emptied into the separator which ejects straw and chaff from the sample when turned on.

Remaining grains are then weighed using a small set of scales.


The weight of grain is input into a smartphone app, along with other data, such as crop type and yield, machine width and operating speed. A figure for

losses is then calculated. Mr Chamberlain reports the app is simple and intuitive to use.

Typically, a trailer driver will be in charge of the process, with data, such as yield and moisture, communicated via walkie talkies and the result transferred back to Mr Chamberlain.

The figure given from the app is then used to calibrate the combines onboard loss monitor.

However, more than that, it gives him reassurance that he is running at the optimal speed when harvesting.

If I can run at an extra 1kph while maintaining reasonable losses, I can potentially harvest an extra 10 acres each day, which really pays for the system when it

comes to maintaining the quality of milling wheat.

In the first year the system was installed on the farm, an increase in forward speed of 18% was seen, while maintaining the same losses, says Mr Chamberlain.

He has also investigated other ways the system could be used.

We run a high clearance self-propelled sprayer, which comes into its own when desiccating OSR. By putting a drop pan in the tramlines we reckon we shed 0.9kg/ha of seed in the tramline when spraying with our 32m sprayer. However, we have heard reports that with a 24m trailed sprayer, losses when

desiccating can rise to 24kg/ha.

Without the Bushel Plus, obtaining these figures would be difficult, and it helps to justify our investment in machinery.

He adds that for a relatively small investment, the system has improved the accuracy of harvest, allowing precise measurement of losses and finite adjustment of

speed, safe in the knowledge the crop is getting into the tank in the fastest way possible.

Mr Chamberlain expects the system to perform for at least 10 years, spreading the initial purchase cost and helping the farm cut more quickly and maintain quality on its high value crops.

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