Looking to spread muck more accurately and efficiently, one Shropshire farm has turned to K Two’s Bio model muck spreader equipped with weigh cells. Geoff Ashcroft reports.
Spreading about 15,000 tonnes of chicken muck each year for its own needs and as part of a contract spreading operation for customers, Shropshire farming firm J A and O Griffiths, of Ellerdine Grange Farm, has recently improved application accuracy.
“Spreading solid muck is never going to be up there with the accuracy of a fertiliser spreader,” accepts Alex Pike, one of the farm’s managers. “But recent advances in kit has at least removed the guesswork from application.”
With the farm’s muck spreading tasks extending from spreading on grassland, stubbles and running down tramlines - the latter considered a useful top dressing role in spring - an element of greater traceability was deemed necessary.
And the ability to determine and control application rates independently of forward speed, while creating a spread pattern that could suit tramlines, was considered the way forward.
The 18-tonne spreader handles around 15,000 tonnes of manure each season.
Kit for the task includes a K Two Bio 1800 rear discharge spreader, equipped with on-board weighing and an automatic rate controller. Bought three years ago to replace a five-year old K Two spreader that was returned to the manufacturer for refurbishment, Mr Pike says the farm has never looked back.
“While the weighing system is essentially a guide to what you’re applying, our poultry muck is very consistent in content and density,” he says. “We feed birds the same diet, they’re the same breed and they are reared the same way. It makes muck management a known quantity.”
“And given that we have a tremendous source of nitrogen at our fingertips, we want to make the most of such resources,” he says. “And the best way forward, was to use a more sophisticated spreader.”
The K Two Bio combines an RDS 8000i controller and four weigh cells – two on the drawbar, two above the rear axle, recessed into the spreader chassis. This design suspends the body in a way that avoids any additional subframe construction. It also means the spreader’s overall height remains unchanged.
With muck analysis providing the basis for nitrogen values, the operator can enter the spreading width and desired application rate into the control box.
The spreader then automatically regulates bed speed, according to forward speed, to achieve the required rate.
“If we travel too fast while spreading, and the system can’t keep up, we get a warning on the control box to slow down,” he says.
A front-mounted sight gauge indicates slurry door position.
Mr Pike says the spreader’s weigh cells are checked and calibrated each season using the farm’s weighbridge, adding that the spreader is accurate to within 2 per cent.
“When we deliver muck to customers’ premises, it is weighed as it leaves our farm,” he says. “We know how many tonnes are in a heap, which also makes it easy to regulate. Based on nutrient analysis, we can apply up to four tonnes/acre to comply with NZV rules.”
“Our payload is typically 18 tonnes, but we’ve had much more in there - the scales don’t read beyond 26 tonnes,” he says. “And despite the low rolling radius of the spreader’s 710/70 R42 tyres, we need a minimum of 200hp to be on top of the job.”
Power for the spreader comes from a Fendt 936 Vario equipped with RTK and steering guidance, but the farm has also used the machine behind its Challenger MT765C.
“Tracks provide the option of low ground pressure when we’re running up and down tramlines,” he says. “And RTK offers accurate bout widths when we’re spreading on grassland.”
Mr Pike’s experience of using K Two spreaders has led to technical improvements in a couple of key areas. One is the addition of hinged vanes on the spinning discs.
“When we clear a muck heap from a field, we can’t leave any trace of manure on the ground,” he says. “This often means we end up taking a bit of soil too, and that can sometimes mean stones.”
He says stones can cause issues with fixed vanes - if trapped, they will be slammed against the outer frame of the disc bed, leading to a bent vane and the potential to warp the spinning discs.
Spinning discs get hinged vanes to reduce damage from any foreign objects.
“There’s a lot of energy in there,” he says. “Our solution was to use a vane with a hinged end-section, so it could break-back and reset itself once an obstruction had passed.”
“We started with extra weight on the back side of the vane to help it hold station, but they go round so fast for a 24m spread pattern that they’re not necessary.”
The other area of improvement is the use of a mechenical indicator for the rear slurry door setting.
“Door position is essential for us to regulate flow through the horizontal beaters and onto the spinning discs,” he says. “We had to guess the slurry door position until we helped to develop a sight gauge.”
The wire rope operated gauge is located on the front of the spreader, by the drawbar, and gives a quick visual reference of how far the door has been raised.
“We typically run with the door at 30-50 per cent open,” he adds. “This setting allows the beaters to shred muck, and carry out a mulching operation, which improves the spread pattern.”
Despite the occasional electronic gremlin - the farm often leaves a few kg in the spreader rather than emptying it fully each time to help stabilise the rate controller.
“We’re no longer dealing with a waste product that used to be piled onto fields at any opportunity,” Mr Pike says. “We’ve improved the value of our manure by spreading it accurately, and efficiently.”