With the spotlight increasingly being placed on the management of livestock slurry, from storing it to spreading it, from compliance to its utilisation, the focus on slurry has intensified. This focus isn’t going to shift anytime soon and, if anything, it will intensify.
To get a glimpse of what some of the European manufacturers are doing, we were invited to Vogelsang headquarters, where we looked at separation, stabilisation and the company’s latest technology.
Based in Essen in western Germany, Vogelsang has been at the heart of slurry equipment development for years. In this region of Germany, one in every two pigs is produced. In fact, adjacent to Vogelsang headquarters is a pig slaughterhouse, where 13,000 pigs are processed each day.
Vogelsang was established in 1929, and veered into pumps in 1970 when it built its first lobe pump. In 1980, Vogelsang designed and built the first dribble bar, with the initial design built to help reduce odour from the slurry.
Today, the firm builds over 800 dribble bars and trailing shoes annually, supplying 30 OEMs. It has five factories, with approximately 30% of the business dedicated to agriculture, 30% biogas, 30% industrial.
All components and equipment is built in house, with the exception of motors and gearboxes. The third-generation company has a turnover of €202m, and employs over 1,300 staff across 50 locations worldwide. The firm set up an Irish subsidiary in 2011, which is one of 25 subsidiaries.
The Irish subsidiary provides training, support, service and spare parts for all equipment working in Ireland.
New macerator
Vogelsang became best known in Irish machinery circles with its macerator. The company has been making macerators since 1980, when it built its first dribble bar.
The Germans’ opinion on Irish slurry is like that with our grassland machinery – if it works in Irish conditions, it will work anywhere in the world. On the back of this, the company has put a huge emphasis on testing all new macerators and applicators in Ireland, before globally launching any product, as it noted that Irish slurries tend to be the most difficult in the world.
After three years of extensive testing of its heavy-duty (HD) ECQ, ECM and ECC units in Ireland with farmers and contractors north and south, it is keen to demonstrate its new macerator’s abilities.
Until recently, all macerators on the market were equipped with ventilation hoses and air suction for even flow of the slurry into the discharge lines.
Vogelsang has unveiled its new ExaCut ECC, which is the first Vogelsang macerator without the required external air suction. It says the ECC was developed primarily for use on slurry injectors for the Dutch market, where air suction can often lead to problems and, secondly, where regulation states that slurry dripping on the soil surface is not permitted.
The new ECC has a rotor concept, which prevents the formation of negative pressure. The firm claims this leads to very smooth distribution without pulsation of the hoses. An eccentric adjuster ensures that the cutting blades always exert a constant pressure on the cutting ring.
The company says it has a power requirement of 25-30l/min. Features, such as self-sharpening cutting blades and the high cutting force, are retained. It’s available with 30, 40 or 48 outlets.
New trailing shoes
The Blackbird trailing shoe range is Vogelsang’s flagship offering and is where the company has recently unveiled its latest designs. The company prides the range on several factors; firstly, its ability to apply up to 12kg coulter pressure per shoe, its slurry placement due to the flow-optimised shoe and its slurry distribution accuracy independently measured by DLG (test report 7030). The entire Blackbird range is horizontal-folding and chassis-mounted.
The range includes the BlackBird Single, Light, Pro and Max. The Single is available in 7.5m, 9m, 10.5m and 12m. As the name suggests, it is available with a single macerator only and is designed to be light in weight. For example, its 7.5m weighs 870kg, its 9m version weighs 930kg, its 10.5m weighs 990kg and its 12m version weighs 1,050kg. When the single range is fitted to a 2m diameter barrel, it offers a 2.55m transport width. As standard, it’s fitted with the HD ECQ macerator, with the option of upgrading to the heavy-duty ECM.
The Light range comes in 12m and 15m. It’s a twin-macerator range, which uses the firm’s ECM macerator as standard to keep weight down. When fitted on a tanker with a 2.2m barrel, its transport width is 2.99m.
The Pro range is larger and heavier, and is available in 12m, 15m and 18m working widths.
Again, it’s a twin-macerator range. It comes with the firm’s HD ECQ heavy-duty series macerator, but also has the option of using the lighter compact-mini ECM macerator.
The Max is available in 21m, 24m, 27m and 30m working widths. It’s equipped with two or four macerators, and again comes with the firm’s HD ECQ heavy-duty series macerator, and has the option of using the lighter ECM macerator.
The Max IsoBus features its own control unit, and comes with section control. It’s a super piece of engineering, but it is unlikely we will see too many of them breaking ground in Ireland.
Controlled slurry spreading
All BlackBird models are equipped with the company’s ‘flow-optimised’ PrecisionFlow spout. It has a row spacing of 25cm.
Vogelsang claims that this outlet design is based on flow simulation data, with its geometry ensuring high-precision placement of the slurry.
It says that thanks to a special additional edge, the wear on the skid does not affect the joint shape or the slot.
The firm also presented its ‘DoubleFlow’ system, which divides each singular outlet into two outlets.
The trailing shoe outlets are divided into two through a Y-piece. This halves the row spacing from 25cm to 12.5cm when spreading slurry.
It also effectively doubles the area coverage without affecting the tractor’s forward speed.
The new option is available on the UniSpread and BlackBird trailing shoe ranges.
Vogelsang says it uses a lightweight construction concept to keep the weight of the Y-flow distributor at the same weight as the standard applicator.
The system is made from replaceable Hardox steel blades and wear-resistant plastic and can be retrofitted.
New night-time work lighting
With the NightShift equipment option, Vogelsang claims it is the first manufacturer of slurry technology to offer complete work lighting for its spreading systems.
The LED lights are attached to the pole frame at a distance of one metre.
The main light output is emitted downwards, illuminating the working area of the boom. The lighting can be combined with the new, digitalised EasyControl toggle switch control and dimmed to the appropriate light level. 
Macerator options
The company now has four macerator offerings; the 62kg ECM, the 80kg ECL (the most popular model on the Irish market), the 94kg heavy-duty (HD) ECQ- designed for the Irish market and, finally, the new ECC breatherless macerator which also weighs in at 94kg.
The company says the new HD ECQ macerator has been specifically built to Irish specifications.
It features a chamfered blade and heavy-duty rotor for superior cutting performance and even distribution of slurry to all hoses.
It claims its low oil flow requirement of 30l/minute extends part wear life by up to 50%, while the front service hatch ensures easy maintenance and user-friendly operation.
With the focus in some Scandic countries moving from nitrate emissions to ammonia emissions, Vogelsang showcased its slurry stabilisation system, which essentially adds sulfuric acid to slurry. This, it says, helps to significantly reduce nitrogen loss when spreading slurry.
The pH value is the decisive factor in slurry stabilisation by acidification.
Vogelsang explained that it defines the relationship between ammonium and ammonia. It says the optimum for the pH value is usually in the range between 6 and 6.5. The initial pH value fluctuates significantly from farm to farm.
Digestate from biogas plants tends to have a pH value around eight, which is more alkaline than cattle manure which is usually around seven.
Vogelsang’s SyreN system offers two different spreading modes, firstly, where it applies the acid to meet a specific pH value and secondly, where a set defined acid application rate is set from the start.
Studies by the Lower Saxony Chamber of Agriculture in Germany have demonstrated increased yield using slurry stabilisation.
Vogelsang says this is due to the higher ammonium concentration and improved phosphate bioavailability. In addition, it says the sulphur contained in the acid also becomes available to the plants as sulphate after spreading.
How the SyreN system works?
The system is mounted on the tractor’s front linkage. The double-skinned IBC tank holds 850 litres of sulfuric acid. The acid is routed underneath the tractor, via one inch stainless steel piping and non-drip fittings to the tanker. A pH sensor continually takes live real-time measurements of the slurry.
The acid is injected into the slurry stream, just before it is applied using a dribble bar or trailing shoe, etc. When the acid is added, the mixture starts to foam, and its volume increases. Vogelsang says this is why it is not possible to acidify the slurry earlier on in the process, such as in the tank.
Dosage rates vary depending on the slurry. For example, typical cattle slurry is treated at two to three litres per m3, while digestate dosing increases to four to six litres per m3. The system is not cheap, with retrofit prices starting from €80,000 plus VAT.
Simply put, slurry separation is a process which involves the removal of the solid, fibrous segment before returning the liquid segment to a storage tank.
With only a handful of units working in Ireland to date, the concept is gaining more traction. Different types of technology are available when it comes to slurry separation. Some examples include screen separation, membrane separation, decanting centrifugation and press separation. Separation using a press is the most popular method. Vogelsang launched its first ‘XSplit’ separator in 2021, and recently introduced a more basic setup for smaller holdings.
The agitated slurry is sucked from the slatted tank using a conventional slurry hose and fed into the separator using a progressive cavity positive displacement lobe pump.
The system utilises such a pump which works on pressure, and can be operated bi-directionally, rather than vacuum. Such a supply pump is required to keep the system consistently running at 0.2 bar in the negative, to maintain suction.
The slurry is fed to the press screw XSplit separator, where the actual separation takes place. The slurry is forced against a screen, which sees the liquid fraction squeezed through and escape downwards via gravity through a discharge pipe at the bottom of the separator. A displacement pump sends the liquid out through a lay flat hose to a storage tank.
The remaining solid fraction is pushed out at the end of the separation cylinder, and captured in a trailer underneath. Different size screens can be fitted, with the final dry faction being screened up to 40% dry matter.
Manual or automatic
The system can be operated in manual or automatic mode. The unit we saw was powered by the farm’s three-phase electrical supply, but a suitably powered generator (minimum output of 415V) will work fine. Depending on the slurry, the throughput capacity ranges from 35-50m3/hr, which is approximately 12.4t to 17.6t/hour.
We visited a nearby farm with 300 dairy cows on an indoor system. With nitrates a problem, the cost to the farm to export slurry to a local anaerobic digester is €15-18/m3. However, if the farmer separates the slurry, he keeps the liquid faction and the anaerobic digester will pay him €5-10/m3 for the solid faction.
New additions
At the factory, Vogelsang showcased a new compact, stationary system solution for the XSplit separator, complete with a pump and control unit. Additionally, Vogelsang introduced the VarioAdjust hydraulic adjustment system for the XSplit press screw separator. This allows for easy adjustment of the contact pressure during operation, a setting to control the desired dry matter content.
What are the advantages?
Manufacturers claim that slurry separators will increase slurry storage by around 20%. This is the big selling point. The separated liquid fraction is also easier to spread and is absorbed into the ground quicker, causing less ammonia loss, less leaf contamination and less potential run-off.
The farm we visited last week was just about to cut its seventh-cut silage, with the first cut only taken in May.
The farmer remarked that before the farm moved to separation, compliance using a dribble bar was leaving the fibres from slurry on the ground, even after the silage had been cut, which is typically every three weeks.
With current compliance meaning many Irish farmers are required to apply slurry using LESS methods, reduced fibre in the slurry would help resolve the issue of lines remaining on the ground as can often be the case after applying slurry after first-cut silage, or if slurry is applied and a prolonged dry spell occurs.
Prices for a basic static separation unit start at €25,000 plus VAT and range north of €120,000 plus VAT for a top spec mobile trailer with automated controls.
Pricing is farm-specific, and depends on a host of factors. Remember, screw press slurry separators are being funded by TAMS III under the Animal Welfare, Safety and Nutrient Storage Scheme (AWNSS). The units are costed based on their capacity in metres cubed per hour throughput.
The unit featured has a throughput capacity of up to 50m3/hr. Based on the TAMS III document, the calculation of a reference price is as follows; y=20.146(50) + 30,875 which equates to €31,882.30.
