Sugar beet harvest is under way. Mike Abram finds out how to set up harvesters to minimise losses.

Every tonne of beet is being paid for by British Sugar at the full contract price this season, and while that might not be the price most growers would like to be receiving, it makes sense to deliver every possible tonne to the factory.

And that means taking care not to leave beet in the field or break or bruise roots as they are harvested. According to results from the British Beet Research Organisation‘s quality harvesting scheme, a harvester in the top 20% will only leave about 0.6t/ha of beet in the field compared with up to 3.5-4t/ha for a harvester in the bottom 20%. The average for all growers is about 2t/ha.

At current prices, the difference between the top and bottom 20% is an immediate £80/ha off a grower’s bottom line.

Setting up and operating the harvester correctly is more than half the battle, British Sugar’s Stephen Brown says. “The operator is responsible for about 70% of the losses, poor maintenance accounts for about 10-15%, while things like crop condition, weed control, seed-bed levelness and the weather all also play a part.”

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The first area in which lifting losses can occur is during topping, where harvesting needs to remove enough leaf for factory acceptance, but not to over-top so the grower loses yield, Mr Brown says.

“Growers obviously also get paid for crown tare, so there is also a financial loss on top of the yield loss.”

Flails need to be set to top beet down to 1-1.5in of leaf on the biggest beet, he says. “They need to be well-maintained to ensure full removal of leaf and to allow optimum performance of the scalpers, especially later in the season when there is more dead leaf to remove.”

Knives should be adjusted to remove the correct amount of crown. “Ideally, leave the beet so you see the bottom leaf scars on the top of the roots,” he advises. “Also ensure knives are sharp so they are cutting the crown rather than breaking it.”

The aim when lifting the roots is to keep them entire and then to clean soil from the beet sufficiently but not cause too much damage or breakage to the roots.

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Most harvesters are fitted with vibrating shears, Mr Brown says. In dry conditions, set a lower vibrating speed, drive slower and go slightly deeper. “If you go too fast, you will snatch the beet from the ground, and because they’re tight in the ground, you’ll break the beet.”

In the wet the opposite applies – use a higher vibration speed, faster forward speed and a shallower depth. “The idea is to avoid too much soil in the harvester, so more vibration and a shallower depth will reduce the volume coming in.”

Similarly, slow down roller cleaners in the dry to avoid beet rubbing against the metal spirals, and speed it up in the wet to pull soil through.

The same principle applies to the more common turbine cleaners, Mr Brown says. “And make sure the turbines and the turbine gates are in good condition, with no broken fingers or pigtail gates.

“Set the distance between the gates and the turbines to be sufficient to take out soil and trash, but not let any beet through.

“Under very dry conditions, you can fit rail gates or plates onto the pigtail gates (pictured) that cut down bruising.”

When unloading, always keep beet in the bottom of the tank to cushion the fall of roots and try to minimise the drop height into trailers. “When tipping in the clamp, don’t reverse into it so you crush roots with the trailer wheels and again tip beet on to beet.”

Avoiding bruising becomes even more important later in the season. “The normal total sugar loss in the clamp is 0.12% a day from 1 January. If you badly bruise beet during harvest, it can add another 0.2% loss on top, which – with late delivery bonus at 0.2% – means you’re actually losing money not gaining it. It also has an impact further down the line with more likelihood of rots setting in.”

Early yields show potential

In almost ideal lifting conditions initial yields and sugar contents have been extremely promising, says Paul Bee of British Sugar. “Root yields are looking high, with average or higher sugar contents we look in for a very good yield. It is going to be better than last year, and we’re hopeful of averaging 65t/ha.”
Sugar levels at the Wissington factory had risen from 16.5% at the beginning of the campaign, which started on 22 September, to 17.1% last week, factory manager Mark Culloden said. “Newark has been even better, averaging 17.3%.”
Soil tares were generally low (three to fours), crown tares were about 8.5-9%, while amino-Ns were low, too, he added.
“The crop is also healthy, so we should see some good autumn growth. Now we just need to optimise root recovery from the field to the factory.”

BBRO quality harvester scheme

BBRO’s quality harvester scheme measures performance through some straightforward in-field investigations.

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First, the biological yield of the field is taken by digging and weighing 10 roots from four areas within a field. Then, once the harvester has lifted the crop, any whole roots left on the surface or in the ground from four areas of 20m by six rows are weighed to measure surface losses.

“I would want to pick up no more than four small roots to be doing a good job,” Mr Brown says.

Root breakages are calculated by taking 100 roots from the clamp and measuring the degree of root breakage using a crocodile tool. It measures breakages on a scale of 0-5. “The aim is for 90 roots to have no greater breaks than a finger width, and 10 with no greater than two finger widths.”

The two assessments are entered into a computer programme, which calculates the total losses for the harvester test. The aim is for total loss of no more than 2t/ha.

About 200 of the tests are due to be carried out this season, with the results published on a monthly basis, together with some seasonal tips to improve efficiency.