12 September 1997

Call for year- round SP tests

FERTILISER spread pattern ratings need assessing throughout the year to check for variations between batches, says a leading spreader manufacturer.

"Samples – not submitted, but randomly selected from the manufacturing plant by the body conducting the analysis – should be regularly spot-tested," says Rod Baker, managing director of spreader maker Amazone.

"If any variation in specification, within reasonable parameters, is found, the manufacturer should be given time to correct the fault or the SP rating should be withdrawn."

Publishing the results would help satisfy farmers that the classification – on which they may have based purchasing decision – holds true for the season, he adds.

The Fertiliser Manufacturers Association should also use the new equipment at Silsoe (Arable, Aug 29) to check the physical characteristics of fertilisers and print them on the bag, he says. "Users would then have a basis to refer back to should they have problems spreading the fertiliser."

Barry Higgs, director general of the FMA, says Mr Bakers proposals are being considered. But testing at Silsoe is costly at £1000 a sample. As an alternative the FMA is looking at the scope for merchants to check physical specifications at the manufacturing plant during the season, as a guide to spreadability.

However, regular machine calibration is the growers best guide to good spreading, he stresses. &#42