Design of wide heavy rolls ensures consolidation challenges overcome in min-tilled crops

For Northampton farm manager, Nathan Kilby, consolidation is king. Since switching the entire crop establishment approach at Manor Farm, near Towcester, across to direct-drilling three years ago, he has realised just how essential it is to roll stubbles after drilling. Not once, but twice.

“The rolls are now the most important bit of kit on the farm,” he explains.

“They do an essential job in a conventional system but they’re even more critical in a no-till situation.

“When we first made the switch from min-till to direct-drilling we had our old set of 12m rolls that had always worked perfectly for us. But running on stubbles they were simply not heavy enough to create enough downforce and have a positive consolidation effect. We needed to take a step up in this critical part of the operation.”

When he started looking into it, he realised that the options for bigger, heavier rolls were limited, especially as he wanted to find a set that fitted within the farm’s 36m tram-lining system.

“As we’re direct-drilling we wanted to limit the number of passes we make and certainly stick with our existing wheelings. A true controlled traffic regime isn’t really practical for us but with a 9m drill, 9m combine header and 36m sprayer, it made sense that our new rolls should be 18m.”

Having researched the various options he decided that Opico’s HE-VA King Rollers fitted the bill perfectly and offered the best value for money.

“Weighing in at 14t, the HE-VA rolls looked to be solidly built and cleverly engineered in the way they fold, and also the way that weight is distributed across the full width.

“By having each of the five sections hung from a central pivot mounting, they can accurately follow contours and at the same time the way the hydraulics are plumbed means downforce is always even across the full working width.”

HE-VA’s SAT (Special Active Transfer) system uses some clever plumbing to ensure each of the King Roller’s five gangs adapt to contours and follow the ground as faithfully as possible.

The entire hydraulic circuit is linked to two gas accumulators and a pressure gauge. This allows the operator to set the amount of weight transferred onto the outer wings to maintain an even pressure across the full working width.

The accumulators act as an oil buffer when the rolls are travelling across uneven ground, taking up and releasing oil as the rams extend and retract but maintaining an even pressure all the while and making the most of weight from the big roller’s hefty main frame and chassis. And, despite their size, moving from field to field is no issue.

“The way the rolls fold is clever and relatively quick so it’s not a chore moving them. They travel remarkably well given their weight.”

Now going into their second season at Manor Farm, the King Rollers have certainly 0lived up to expectations, especially when it comes to work rates.

“With such a wide wing-span we can travel at the right speed to do a decent job – generally around 8kph (5mph) – and we can still comfortably cover 120ha/day (300acres/day),” explains Mr Kilby.

“At that pace our 160hp Valtra can easily keep up, even on our steep banks, and we have the output to get everything rolled twice. That way we’re ensuring good seed-to-soil contact and moisture conservation. More importantly, we make the ground as inhospitable as possible for slugs.

“And with plenty of problem grassweeds we’re also generating a much better weed flush which means we’re getting better control.”