HARVEST SEASON 2019 was notable for many Scottish farmers reporting problems with their machinery – and pointing the finger of blame at biodiesel.

In a joint statement on the issue, equipment and input sharing co-op Ringlink and NFU Scotland have this week offered advice to their farmer members who find their machines have been affected.

Reported issues in tractors and harvesters include poor performance, blocked filters, low working hours before filter changes are required and injector failure. Due to the number of vehicles now affected, some areas are experiencing filter shortages and a lack of workshop availability for the required repairs.

"There is a large amount of speculation about what might be causing the widespread problems," read the joint statement. "Most of this is directed at the Fatty Acid Methyl Ester (biodiesel) content of the fuel being supplied. Biodiesel is manufactured mainly from recycled oils but can be a blend of renewable and recyclable material including tallow and plant oils. The recycled oil has been blended into diesel to make the diesel more environmentally friendly by using less diesel sourced from crude oil, reducing emissions and thus helping air quality."

Since the issue was first raised, NFUS has been compiling evidence from members and machinery rings to try to identify if there is any discernible pattern to the problem. It has also been in contact with representatives of the UK Petroleum Industry.

In tandem with Ringlink, NFUS has paid for independent testing on three separate fuel samples to try to identify the cause of the reported problems – and these tests have shown that there is no issue in terms of the FAME content of the fuel tested, which is within the prescribed limits set out in legislation. The union now has a meeting scheduled with Petrolineos, operators of Grangemouth refinery later this month, but is currently working to get this meeting brought forward.

"There are no apparent patterns with regards to make, model, or type of machinery affected," said the joint statement. "There are also no links with specific end suppliers, although geographically the issue is being seen from central Scotland down to the Borders.

"In the first instance, members should consult their fuel supplier regarding individual advice. Some suppliers are suggesting specific additives to help address any issues with bacterial growth in storage tanks. However, members should ensure that these are compatible with the specific machines utilising the fuel before taking this course of action," it advised.

"Members should ensure that their fuel storage husbandry is up to date. Storage tanks should be thoroughly cleaned out and where possible this should occur before each new fill. This will prevent potential issues caused by water ingress, dirt, mould or bacterial growths. Where fuel is to be stored for long periods of time, members should consult their fuel supplier for their best advice, for example in relation to larger storage tanks or combines.

"Storage tanks and fuel delivery systems should all be fitted with filters, to prevent contamination between tank and machinery," added the statement. "It is prudent to keep a supply of spare filters for machinery and storage tanks to prevent down time if these require to be changed."