Despite its slightly novel appearance, Veenhuis reckons its Rotamax umbilical system has a number of benefits.
Richard Bradley caught up with the firm bringing the Dutch-built machines over to the UK.
Traditionally, spreading slurry and digestate onto arable land was done with either an umbilical or tank-based system.
The former is restricted by the effects of drag on hoses, while the latter requires either a large tanker or self-propelled machine.
Aiming to combat this issue, Dutch slurry handling specialist Veenhuis has developed a rather intriguing looking hybrid umbilical outfit. While not at all a basic machine, the Rotamax features a large pipe reel and arm, and a 12-metre injector unit, all on a trailed chassis.
The advantage of the system, according to the firm, is its ability to pick up and lay down pipe without having to drag it across the ground as the machine travels up and down the field.
Firstly, this means the pipe is not disturbing or damaging to crop or soil, nor does the tractor have to work against the drag on the pipe.
One company which stumbled across the Rotamax while browsing the internet went out to Holland in early 2016 to see it in action. By the end of its trip, Technical Waste Solutions (TWS) had bought itself a machine, along with becoming the UK distributor for Veenhuis equipment.
TWS spreads up to 150,000 tonnes of digestate and food waste per year, most of which is carted in for the 810-hectare (2,000-acre) arable farm on which it is based.
John Crooks, one of the TWS directors, says: “Previously, we were using umbilical systems and two large tankers for spreading duties, with injectors and 24m dribble bars.
“The problem with the tankers is they have to run along the field fully laden, causing compaction issues. On the other hand, a traditional umbilical system is limited to the length of pipe the tractor can pull, and causes disturbance to soil and standing crop.”
“We are running the outfit with similar pump and pipe setups as we would with a normal drag hose system. The only difference is the way you reel pipes out and the way you cover a field.
“It allows us to operate over a larger acreage to an equivalent drag hose setup, and the Rotamax is much quicker to setup and breakdown at the end of a job or between fields.”
At the heart of the Rotamax is its hydraulically powered reeler, which is capable of holding up to 700m of 115mm (4.5inch) umbilical pipe.
However, unlike a conventional reeler, the pipe on the Rotamax is filled with liquid, then kept filled for as long as is convenient. A valve is fitted to the furthest pipe coupling to keep pressure maintained.
The second fundamental element is its pipe-carrying arm. This hydraulically pivoting arm features a series of rollers, allowing the pipe to be dragged onto or pulled off the reeler.
After connecting the umbilical pipe to the spreader’s on-board pipe, you can make your first run up the field with the arm laying its pipe onto the edge of your next run.
As you make your way back down the field, it is pulled back onto the reeler, and so on with each pass. By connecting to your umbilical pipe in the centre of a field, maximum working area with the pipe on its own back is 40ha (99 acres), according to Mr Crooks.
He also says the arm can be set to lay the pipe in-between rows, or into tramlines, to further reduce any chance of crop damage.
He says: “As you are not dragging pipes, and the only pulling requirement is of the injector and the spreader’s wheels, 140hp easily manages the machine.
“Running with a smaller tractor, along with an on-board central tyre inflation system and an axle which hydraulically extends in the field, helps reduce compaction.”
Taking care of spreading, the Rotamax is fitted with a 12m single-disc injector. Unlike here in the UK, Mr Crooks says due to regulations stipulating slurry or digestate can only be applied into soil, and not onto the surface with a splash plate or dribble bar, injecting into standing crops is common practice in Holland.
He says: “We are seeing more and more people trying to make the most of their resources, and as injecting provides the lowest losses of readily available nitrogen, it allows them to get the most out of their slurry and digestates.
“We are trying to get growers on board with injecting into standing crops. We have injected into cereal crops up to 300mm (12in) tall with no issues. We are, however, looking at getting a trailing shoe as the next-best alternative to bridge the gap.”
Another interesting element to TWS’ pumping outfit is the way it co-ordinates itself at headlands and on shortwork. Thanks to radio telemetry control of the engine-driven centrifugal pump, the Rotamax operator is able to increase and decrease flow rates from their cab, without the need for a second operator.
Mr Crooks says: “As we approach the headland and the injector is lifted out of the ground, each nozzle is shut off and the pump automatically drops its revs to maintain pressure in the system.
“This works similarly on shortwork, although the operator will often just increase forward speed as nozzles are shut off to maintain application rate.
Rollers on the arm allow pipe to be pulled on and fed off by the hydraulically-driven reel.
“A valve on the spreader is constantly adjusting itself slightly to maintain pressure in the pipe on the reel, reducing the chance of it collapsing.”
Thanks to an IsoBus connection, shut-off is controlled automatically via the tractor’s GPS signal.
Another element to the machine which should help improve the way slurry and digestate is applied, is the option of fitting a near infra-red sensor for real-time analysis of N, P and K.
This allows the operator to set application rates based on nutrient content, rather than simply setting a liquid rate. As the liquid’s nutrient content changes, the tractor’s forward speed can be increased or decreased to suit.
If more than one nutrient is required, the firm can add a front tank to top up the digestate’s values artificially.
Once the Rotamax has finished in a block or field, breaking down the system takes a different tact to a regular umbilical setup.
Mr Crooks says: “When moving from jobs, we want to keep the 700m pipe on the reeler full, where possible. As we know the length and diameter of pipe from the pump, we can work out the volume.
“Before we start blowing the system out, we pump 1cu.metre of water down the line, followed by the sponge. The operator then counts down the volume on the flow metre, and shuts the valve when there should be just 0.5cu.m of water left in the pipe.
“Then, they disconnect the Rotamax’s pipe from the system and open the valve, which blows the water and sponge out onto the field.
“This makes blowing out a lot quicker than a conventional umbilical system. Places with irrigation mains are also ideal, as we do not have to blow out, speeding things up further.”
While its first Rotamax has now been sold, the firm has a second machine for its own use and demos, and aims to spread 100,000t with it in 2018.
Mr Crooks says: “The Rotamax has extended our spreading window compared to our umbilical outfit, as we do not have the issues of dragging pipes on wet ground, and we are not travelling across the field with the same weight as a high capacity slurry tanker.”