Improvements to silage quality from using additives are widely acknowledged, but applicators usually have to be fitted as an addition to harvest machinery rather than being built in. Jane Carley gets to some advice on the best way to fit and use the equipment.
Silage additives help to preserve the ensiled forage crop, maintaining its nutritional quality and can assist in reducing spoilage by improving aerobic stability.
Depending on the type of forage and its moisture levels, either chemical or lactic acid bacteria inoculants can be applied on the harvesting equipment, be it chopper, wagon or baler.
However, as the range of equipment on the market varies so widely there is no ‘one-size-fits-all’ solution.
Of the silage additive used in the UK, 95 per cent is wet applied, with the acid or bacteria content supplied as a concentrate and diluted for use.
On a self-propelled forage harvester, additive can carried either in an in-built tank or in 200 litre barrels mounted at the rear of the machine. It is then transferred via a diaphragm or stem pump and applied to the silage via the bottom inspection hatch on the chute at a rate of 1-2 litres/tonne.
Another approach is ultra-low volume (ULV) application, which at 20 millilitres/tonne requires just a 20 litre tank to cover 1,000 tonnes of silage, compared to the 1,000 litres required at 1 litre/tonne. This ULV tank can also be built-in, such as on the Actisyler system integrated into the Claas Jaguar, or retrofitted.
“The low volume tank will last most of the day, and even if a refill is needed, the support driver just needs to bring a two litre bottle of product,” comments Volac silage specialist Peter Smith. “ULV application either uses a nozzle either to vaporise it into the chute or places it in the accelerator to be vaporised when air is drawn into the harvester.”
Mr Smith comments that some farmers were initially sceptical of the efficiency of ULV application, but tests of 30 samples treated by the Actisysler showed that it is as accurate as traditional higher volume application.
“ULV systems are reliant on air speed and need a high volume of air – which can be up to 140mph on modern machines - to atomise the liquid, so may be less suitable for older foragers,” he points out.
Trailed foragers work well with a 200 litre barrel, with the product applied via a diaphragm pump onto the pick-up reel.
Dry application comes in for forage wagons, with the advantage that a 20kg bag of the dry product is relatively easy to carry in a tractor cab, comments Mr Smith.
“An 80kg hopper can be mounted on the front of the wagon, and the powder is blown via a fan in front of the feed rotor. One downside is that the product may bond less well on dry crops, and in windy conditions can blow into the air or fall onto the ground. In addition, if the machine is left overnight without cleaning, product can get wet and sticky,” he says.
Liquid systems are increasingly common on wagons, and tanks can be mounted on the front of the body as long as it is not a moving headboard type. Liquid is piped down to spray on the pick-up reel, ideally via two or three nozzles.
“The higher the nozzles are positioned the better, as they can easily get knocked off. Alternatively, if the knife chamber can be accessed, fit them to spray in front of the knives,” suggests Mr Smith. “However, it is more difficult to check for blockages in this position – fitting a pressure gauge or flow meter for either position will quickly reveal any issues.”
Tank size is worth considering, he points out. “You can choose 200 or 400 litre tanks; additive does not mix as well on a forage wagon as the crop is loosely chopped, so two litres/tonne is the recommended dose, favouring the larger tank.”
On a baler, the nozzles need to be in front of the knives so should be placed as high as possible, spraying down onto the pick-up reel and covering its whole width.
“Aim to apply three litres/tonne or two litres a bale, depending on its size; the Ecosyl Ecobale applicator works well at 250 litres, or you could use the 400 litre tank from a forage wagon.
“Some customers will carry the additive container on brackets on the tractor’s front linkage, but bear in mind that this makes for a longer unit on and off the road and risks covering lights and indicators.”
Automatic applicators can make for more accurate use of the product and get the best out of modern high value balers, suggests Andrew Snell of the Profitable Farming Company (PFC), which supplies branded Hayboss systems to OEMs including Agco and CNH Industrial as well as aftermarket solutions, and the Baler’s Choice range of preservatives.
“A simple manual system will give a set rate based on tonnes/hour baled and can be an economical solution for hay preservatives. An automatic system links application to moisture levels, read by sensors on the pick-up, and applies a variable rate. On balers such as the Fendt Squadra, the system can also use its electronic weight/length measurement data.”
Mr Snell recommends that nozzles should be fitted above the rotor or packer to ensure an even feed, with brand specific kits available from PFC to fit the various balers.
“CNH Industrial and Agco supply theirs factory-ready for electronic and mechanical integration, other makes will need drilling,” he says.
When mounting tanks, Mr Snell cautions that they should be compliant with transport legislation. “Putting a tank on the drawbar means it is overloaded; it should go on the top of the bale chamber itself. Bear in mind that a full tank could also put a round baler overweight on the road so think about transport solutions for water; there is more weight tolerance on a square baler.”
Strength and build quality for mounting systems is vital, he points out. “Do not just think about vertical load, but also lateral movement and deceleration – the design and construction has to be able to cope with a 50kph impact. CE-compliant welding is also a must and few farm workshops can offer this – we use a local shed-building company for welds.”
Mr Snell suggests that a front tank can be useful where contractors are swapping between balers; nozzles can be fitted to both balers and the manual control moves over.
“But think about quality again – we fit plastic non-drip fitting for the pipework and side indicator lights on the tank frame.”
A transfer pump to allow filling from ground level is a useful addition he suggests, avoiding manual lifting.