For all the technology found on spinning disc spreaders, the task of applying prilled or granular products remains a mechanically crude affair. No surprise then, to find some operators carrying out their own tray tests to keep a watchful eye on fertilisers. Geoff Ashcroft reports.
Despite using a high-tech ZA-TS spreader, Dorset contractor George Mogridge will tray test about 10-15 fertiliser products each season to ensure his customers get the best from their fertilisers.
Spreader firms have made big strides in recent years with spinning disc spreaders. Electronic dosing and weighing, section control and auto stop/start all have their place in making fertiliser spreading as precise and efficient as possible.
It does perhaps put fertiliser types under the spotlight for those seeking the ultimate in application accuracy.
For Dorset contractor George Mogridge, based at Shaftesbury, he supplements his high-tech Amazone spreader with a set of 16 test trays, which were supplied new with the machine.
Tray testing during the season can reveal exactly where and how fertiliser is being applied.
He says: “As a contractor applying customers’ own fertilisers, it is vital my business continues to provide the best possible service to get the job done accurately and efficiently.
“Reaching for a set of trays is the only way to know exactly what is going on when there is a change of fertiliser type during the season.
“It gives us flexibility to check there and then, rather than having to call a spreader test firm in to carry out additional tray tests for us.”
George operates a two-year-old ZA-TS Profis Hydro 4200 spreader, which is his second spreader to be equipped with weigh cells.
He is a firm believer in the use of technology and makes full use of apps to support machine settings and fertiliser types.
“A lot of my customers have woken up to the potential to save money, simply by putting the right amount on, exactly where it is needed"
- WILL MOGRIDGE
But having seen how flow rates can change during the course of a day’s spreading, and often in response to changes in weather conditions, he prefers to back-up the electronic wizardry with occasional tray tests.
George says: “There have been a few fertiliser products which have tripped us up in the past. And the trouble with fertiliser applications is you do not know where mistakes are until it is too late.
“So whenever we encounter a change of fertiliser at the beginning of each season, we will get the trays out to double-check what is going on and where it is going.”
He reckons the business applies about 10-15 different fertiliser types for its customers, and anything which has not been through the spreader before will be tray tested as a matter of course.
Information gathered from tray testing provides the business with a baseline, from which spreading can be fine-tuned. And it has proved to be a decision which has paid off.
He says: “As a result of our attention to detail, we have picked up fertiliser application work off the back of others’ mistakes.”
“It is easy to check what’s happening when we come across a change of fertiliser type or a different supplier,” says Will Mogridge.
George says the drawbacks of frequent tray testing are few and far between, although you need to ensure tests are completed in dry conditions.
He says: “It is really a two-man job and it can slow you down a little, but what we have found is it is worth double-checking the technology, because fertiliser varies enormously.”
This is a view shared by George’s nephew and spreader operator Will.
All of the firm’s spreading takes place at 24-metre working widths, either on tramlines, cultivated ground or grass.
While tramlines afford an easy way to maintain a set working width, working with autosteering or lightbar guidance – depending on tractor availability – ensures a consistent bout width in all field situations.
“The next step has seen us recently start to make variable rate applications for one customer"
- WILL MOGRIDGE
Will says: “While grassland is a lot more tolerant of larger variations, we have found even if your driving is not absolutely spot-on, the GPS mapping makes sure the spreader is constantly adjusted to give the right coverage at the right application rate. And the hydraulic disc drive has a key role to play.”
Will says the smarter farms he works with are buying less fertiliser, simply because overlaps are being reduced.
He says: “A lot of my customers have woken up to the potential to save money, simply by putting the right amount on, exactly where it is needed. The next step has seen us recently start to make variable rate applications for one customer.”
Aware of the harsh and corrosive nature of fertiliser and the complex integration of electronic components, the spreader is subjected to a thorough wash-down at the end of each day’s spreading.
Will says: “There is too much at stake to leave things to chance.”
““We do tray test, but prefer to use SCS at the start of each season to provide an element of security with crop assurance and nitrate vulnerable zone records."
- Ed Farquharson
Ed Farquharson of Beech House Farm, Seisdon, Wolverhampton, is all too aware of the importance of tray testing. He used to work with Spreader Calibration Services (SCS) and the background knowledge and training he absorbed during that time put him in good stead on the 500-hectare (1,235-acre) family farm.
He says: “We do tray test, but prefer to use SCS at the start of each season to provide an element of security with crop assurance and nitrate vulnerable zone records.
“With all our fertiliser delivered, we can test different batches, plus three different grades of N and also test the P and K.”
Growing malting barley in the rotation, Mr Farquharson chooses to spend money on better grades of fertiliser.
He says: “Premium fertiliser products do not change much year-on-year. Particle size and spreadability remain consistent throughout the products we choose.”
The farm has traded up its 10-year-old 30.1 Kuhn spreader for the 2017 season to a weigh-cell equipped 40.2 EMC W Axis model from the French manufacturer.
Mr Farquharson says: “Calibration was quite time consuming with the older spreader. If it was practical, we would often recalibrate during the day to compensate for different weather conditions.
“The new machine, with its weigh cells and electronic monitoring, should be much more productive and a lot more accurate.”