Careful planning key to slurry spreading

Expensive, specialist kit means it’s often contractors that are tasked with the glamorous job of slurry spreading, but poor planning and old farm infrastructure often make work slow.

Now, there’s not too much a farmer can do to make things easier without spending big bucks. But for those planning to upgrade or build new facilities, it’s a great opportunity to make life easier for the contractor, according to Wilts-based spreading specialist Paul Joseph.

He reckons that access to stores and hose routes for umbilical spreading should be given full consideration before embarking on a slurry store upgrade of any type. And that includes involving the contractor in the planning stage.

“Having good access to storage facilities for slurry, dirty water and solids helps us do an efficient job with high capacity machinery,” he says. “We like culverts or piped road crossings for umbilical pipework, but they need to be in the right place and big enough to handle the pumping rates we achieve.”

It’s no surprise that improving work efficiency is the key to the business. It must make profits from modest charges and wafer-thin margins as fuel and other operating costs rise. Increasing daily spreading volumes seems to be the only realistic way of doing that.

But efficiency is often limited by the farm layout, with narrow, bumpy access tracks, tight turns and narrow gateways regularly limiting work speed.

While they can be helpful, limited piped road crossings can slow things down, too. If they are too small or misplaced they can restrict the capacity of the contractor’s entire umbilical application system.

Mr Joseph runs different types of slurry and digestate application equipment from his base at Warnborough near Swindon to suit individual circumstances and customer preferences.

“We have a 16cu m vacuum tanker for smaller paddock applications and for spreading slurry to distant locations where we can’t pump for some reason – perhaps because there’s a major road in the way,” he says. “We also run three umbilical teams for biogas plant digestate and liquid separated from slurry, with a splash plate, 6m trailing shoe and 12m drop tube/dribble bar applicators.”

GPS light-bar guidance is used to improve the accuracy of application. An electronic flow meter makes sure the material is applied at the correct application rate and within NVZ limits where necessary.

Each system uses a trailer-based pumping set-up with an engine-driven Bauer Magnum SX2000 centrifugal pump. Powered by a V8 diesel, the pump sends liquid from the store to application sites up to two miles away.

“We’re pumping 140cu m an hour using 127mm pipe and the 12m applicator, with a tractor mounted pump added part way as a booster on long runs. Although the booster pump has to be manned, remote radio control is used to operate the master pump.”

Mr Joseph has been impressed with the Magnum pumps, particularly the maintenance – he says adjustment is needed twice a year at most and they are pretty hard wearing, too.

There is a difference of opinion between contractors and customers when it comes to application method, though. While surface spreading using a low trajectory splash plate machine lets contractors cover the ground quickly, Mr Joseph appreciates that most customers tend to prefer slower dribble bar and trailing shoe applicators.

“Other than injecting, placing slurry gently on the surface using our 12m dribble bar is the best way to minimise nitrogen loss. After several injector applications the sward tends to look a bit cut up so we’re not keen on that technique,” he says.

“Surface-applied slurry is readily absorbed on a well-structured soil leaving very little contamination of the sward. Cattle will happily graze within a few days,” reckons Mr Joseph. “We’ve seen little difference between dribble bar and trailing shoe application, so I’m adding a second 12m dribble bar unit to our service.”

That will increase operating capacity, while investment in bigger diameter hose is also important if the full performance of the pumps is to be exploited.

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