Stewardship concerns as metaldehyde found in water
FARMERS and growers are being urged to follow best practice stewardship guidelines for metaldehyde slug pellet use this autumn following confirmation from water companies across England that high levels of the slug pellet active ingredient are being detected in watercourses in a number of catchments.
The increased levels of metaldehyde follow a period of heavy rainfall, combined with very difficult crop establishment conditions and what some agronomists are describing as unprecedented levels of slugs.
The high slug pressure is affecting patterns of slug pellet use, with use expected to be three times higher in terms of the area treated than in a more typical autumn.
According to Phill Mills of Water UK, which represents UK water companies, a number of companies have been reporting significantly increased levels of metaldehyde in rivers and reservoirs since September this year.
He says: “Peaks in metaldehyde have reached over four parts per billion in several water catchments with some river samples recording their highest ever value since intensive monitoring began in 2008.”
Mr Mills declined to comment on the exact number of water samples showing high levels of metaldehyde but he says the problem is being reported in all regions of the UK, with the exception of the North West.
Dr Paul Fogg of the Metaldehyde Stewardship Group says the organisation recognises some of its stewardship recommendations will be difficult to implement this year. However, growers should not apply any further metaldehyde pellets if applications have reached the 210g/ha active substance limit, he adds.
Gloucestershire farmer and NFU crops board member James Cox says growers are following the metaldehyde stewardship guidelines but are facing very challenging conditions.
- Use minimum active ingredient/ha to avoid drainage and run-off losses
- Maximum total dose August 1 to December 31 210g metaldehyde/ha. For additional protection of water, agronomists may recommended reduced rates of 160g/ha or less active substance
- Maximum total dose rate 700g metaldehyde active substance/ha/calendar year
- No pellets to be applied within six metres of water courses
- Do not apply when heavy rain is forecast
- Do not apply metaldehyde slug pellets if drains are flowing