Catchment management of metaldehyde (UK Pilot Project)

Anglian Water is coming to the end of five years of the Slug it Out trial. The Slug it Out trial is a payment for ecosystem services based approach trialled in key natural catchments from June 2015 until June 2020.

The Slug it Out trial focused solely on agricultural sources of metaldehyde and was designed based on the core tenet of both the “Appraisal of Policy options to Manage Pesticides” report (DEFRA WT0963) and the Metaldehyde Stewardship Groups “high risk fields” approach that regulatory compliant water (individual pesticide level below 0.1µg/l) can be achieved with less than complete exclusion of metaldehyde within a catchment.

The Slug it Out scheme was implemented in seven natural catchments around Anglian Water reservoirs. These were: Grafham, Pitsford, Hollowell, Ravensthorpe, Ardleigh, Alton, Rutland (from 2016/17 onward). A one year trial of the SiO scheme was carried out in the pumped Covenham 1 catchment in 2017/18. In Slug it Out catchments, farmers were paid to not use metaldehyde to control slugs. The amount the farmers were paid was based on the amount of arable land (hectares) that the farm had in the catchment plus a standard hosting fee. An additional water quality bonus was paid if the watercourse had no metaldehyde exceedances from catchment monitoring sampling points. Each catchment had a dedicated Anglian Water Catchment Advisor to engage with the farmers in that catchment and be the link between the Agricultural sector and the Water sector.

The implementation of SiO was successful in many ways and led to a reduction in metaldehyde levels in all natural catchments. In particular, no metaldehyde exceedances were recorded in the five year SiO period in the Grafham, Hollowell and Ravensthorpe Catchments or during the one year trial in the pumped Conveham 1 catchment. Other Catchments such as Alton took a year before not exceeding the pesticide limit while more complicated catchments (numerous additional sources) such as Ardleigh took two years. The implementation of the SiO scheme lead to an average of ~70% reduction in the number of metaldehyde exceedances seen in these catchments compared to the average number of metaldedye exceedances  before the SiO scheme was introduced.

As well as the reduction in the level of metaldehyde in natural catchments, SiO also had other benefits, for example farmers deciding to use cultural controls or ferric phosphate and not metaldehyde to control slugs on land outside of the Slug it Out scheme, thus reducing the overall metaldehyde burden from agriculture entering our raw waters.

The Slug it Out trial also demonstrated that positive and consistent communication between Catchment Advisor and farmers within the catchment – supported by local data is vitally important to success. Another key factor is engagement with local agronomists and other agricultural stakeholders who help disseminate and validate messages while strengthening the building trust of farmers. This itself has led to good two way communication channels benefiting both sectors.  Another important takeaway from the Slug it Out scheme is that providing farmers the financial backing to try something new can lead to positive changes after the payment ends or in areas where the payment does not apply – for example some changes and new ways of thinking benefit the farm business resilience anyway.

As part of the Slug Out scheme drip trays and cab stickers were handed out to all Slug it Out farmers across the seven Slug it Out catchments.–a-proven-success/

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