Here in Ireland there is a thriving engineering sector that focuses on manufacturing slurry spreading equipment, and with such a strong market presence it would be hard to imagine a foreign competitor finding a foothold.
Yet there is one company that has decided to enter the fray and with a product that, it claims, is many years ahead of the homegrown competition.
Building tankers since 1964
The company is Kaweco from the Netherlands, part of the Royal Reesink BV group which, although it is centered around the distribution of farm machinery, does have several manufacturers under its wing as well.
Kaweco is one of those and it has been building slurry tankers since 1964. These would have been of the vacuum type that we are familiar with today, yet in 1992 the Dutch government introduced a ban on splash plates, giving the industry over there a 30 year head start in producing alternatives.
Fast forward to 2023 and its range of machines stand out from the crowd with hardly a vacuum pump in site. Instead, the machines tend to be equipped with positive displacement pumps of various types and the slurry is treated as a valued product rather than something to be got rid of in as quick a manner as possible.
Positive displacement preferred
As cheap and cheerful as the vacuum pump it is not the first resort of the company or its customers, relying instead on positively feeding the distribution heads , and this was certainly the case on the demo unit it sent over for a review here in Ireland recently .
Pump type is but one difference; the tanks are treated with plastic coatings on the inside and are flame sprayed with zinc on the outside rather than dipped in a hot bath, which reduces the risk of distortion in the coating process.
Another departure from the norm is that the range is divided into several distinct types, from the basic, although not that basic, Profi 1 series to the gooseneck units specifically designed to go behind forward cab tractors such as the JCB Fastrac or Claas Xerion.
And while on the subject, Kaweco points out that it is one of only two approved Claas partners for mounting slurry units directly onto the Xerion, making it a factory-fitted option.
Kaweco Demo on tour
Two boom types were sent over to Ireland with the 18,000L (4,000 gallon) Profi II demo unit, a 15m trailing shoe type, and a 8m disc injector.
First out in the field was the trailing shoe which had two distribution heads mounted on it, one for either half. This arrangement reduces the difference in pipe lengths and so encourages a more equal flow to each outlet.
Although Kaweco builds its own dribble bar booms, the trailing shoe boom, weighing 1,500kg, is manufactured by Bomech, a company situated within an hour’s drive of the factory.
Kaweco uses a three-point linkage attached to the rear of the chassis upon which to mount the booms. This is activated by a double acting ram, allowing weight transfer from the tanker to whichever boom type is being used.
The boom also has a certain amount of lateral and vertical freedom of movement which is independent of this mounting, allowing it to cope more easily with undulating ground.
Right hand filling
As a rule, the right-hand side of the tankers are devoted to the filling operation and the left to emptying, thus the control valve for fixing the application rate sits on the left-hand side with the pump directing its full output towards the boom , with the valve diverting the excess bank into the tank.
Presently, this valve can be connected to a prescription map with the volumes applied being based on a prior analysis of the slurry.
There has been an attempt to vary the rate according to Near Infrared Analysis (NIR) of the material as it passes through the machine, yet this has been fraught with difficulties which our own government would do well to take note of.
The major problem is that as a living mix of organic compounds, animal slurry is constantly changing with time, and so the results of analysis can vary widely for the same load. This not only produces a difference between on board NIR systems and a lab, but also differences between labs.
It is a huge muddle and while the ministry might like to tinker with the theoretical figures of the what it is going to allow to be applied, the Dutch experience teaches us that it is impossible to give any assurance that the correct amount of nitrogen is, on a practical basis, being applied.
Kaweco disc injector
The second boom being demonstrated was a Kaweco Opti-Ject 8m Disc Injector which is of the company’s own design and manufacture. Working width was 8m and it weighed around the same as the dribble bar.
Its standard setting discs are set to run at a depth of 2cm with the boot placing the slurry into the slot directly behind the disc. On the day it was dairy washings rather than slurry that was being applied meaning that not all was retained in the slot, but a more viscous material would stay in, and above, the groove.
The disc is a soil-engaging component so the question of the power required comes to the fore. Enda Doran, a leading dairyman and cattle breeder in the area, had the tanker running behind a Deutz Fahr 6185 of 188hp which was coping well with the task on dry ground with little incline.
However, Kaweco would recommend 200hp as the minimum to ensure that adverse conditions are more adequately catered for as the pump alone can absorb 40-50hp when dealing with viscous slurry.
One of the reasons for the ability to pull the tanker over wet ground were the 750/60 tires which were leaving very little impression in the field. A further option is a variable-width front axle which will spread the weight further and ensure even these sized tires would not be running over the same ground.
The Dutch have had a three-decade head start over Ireland when it comes to adapting to farming without the splash plate. Kaweco has used that time to create a range of tankers that is relatively advanced to many of those produced domestically, although they do carry a premium price to match.