Highest risk fields targeted

An industry-wide collaborative initiative is assessing whether field-by-field targeting could be the answer to securing the longer-term availability of metaldehyde-based slug pellets.

With metaldehyde subject to ongoing pressure as a result of detects in water threatening non-compliance with the Water Framework Directive; the Metaldehyde Stewardship Group (MSG) is working with water companies to undertake pilots projects that advocate zero metaldehyde on identified ‘high risk’ fields.

“There is a very strong understanding amongst all the parties involved as to the importance of metaldehyde slug pellets to the agricultural community,” says the MSG’s Simon McMunn.

“This project is very much about securing the future of metaldehyde. There is a real commitment to finding a solution that will avoid a blanket ban. No one wants to see that happen given the limited number of slug treatments now available,” he adds.

The Environment Agency’s Dr Jo Kennedy agrees, “A UK wide withdrawal of metaldehyde would be an absolute last resort – it’s not a course of action the EA currently supports or wishes to see.  We are focussed instead on working with other regulators and industry to find a more targeted, risk based way of tackling the problem – we don’t think a UK wide ban is the solution.”

Catchment areas

The pilot areas have been selected from the high risk water catchments, within ‘Safeguard Zones’ that feed into water abstraction points. They are currently operating within the Mimmshall Brook catchment in Hertfordshire with Affinity Water; and within the Avon and Leam catchment in Warwickshire with Severn Trent. A further two pilot initiatives are planned to be launched in time for the main 2014 autumn pelleting season in the Anglian Water and Thames Water regions.

Maps of each catchment will illustrate fields where no metaldehyde is to be applied, with local agronomists and farmers engaged through a series of regional meetings. Where slug treatment is required within the identified fields, farmers are encouraged to choose an alternative. Cultural control techniques should remain the mainstay of prevention.

Senior Catchment Management Planner, Dr Jodie Whitehead of Severn Trent Water describes how the ‘high risk’ field areas were identified. “All our previous modelling work showed that heavy soils, under-drained fields, gradient, and proximity to a watercourse were the key factors in determining the risk of metaldehyde causing detects in water.

“With official national datasets already in existence for agricultural land, we were able to create maps that a risk score could be assigned to and which would identify the highest risk land, without consigning a very high proportion to the zero metaldehyde restriction.

“This was obviously an area of intense discussion between all the parties involved, and was part of the reason behind the pilot projects. We need to get the ‘cut-off’ level right, and ensure the pilots could be replicated on a bigger scale,” she says.

Jodie adds that previous work with farmers in vulnerable catchments has delivered marked results. “We saw a massive 50% reduction in metaldehyde detection in the wet autumn of 2012 in one significant and vulnerable water catchment. That compared to 2008, which was also a very wet year. These pilot projects build on that success,” she explains.


Alistair White farms 450 hectares on predominantly heavy clay soils on land neighbouring the Affinity Water abstraction station in the Mimmshall Brook catchment, and was keen to be involved with the metaldehyde pilot. “Metaldehyde is our pellet of choice. It works and is reasonably priced. I would be prepared to change our approach to treatment in order to keep metaldehyde – both for us, and for generations to come.”

He believes the practicalities of switching between slug pellets for different fields will be manageable. “It’s not as difficult as switching between sprays, and when you have already calibrated the machine for another pellet type previously, it’s a two minute job to change. I don’t foresee a problem.”

Alistair’s agronomist Tom Scotson, of Procam Agriculture believes that the pilots have a good chance of delivering. “Providing we get grower cooperation, of which we predominantly have got, then it must be the right way to go. We don’t want to lose yet another active ingredient to British agriculture,” he says.


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