Over £10m of funding will be made available for three or four companies to move to the second stage of a Sustainable Use of Livestock Slurry project which aims to reduce the amount of excess phosphorus (P) getting into NI waterways.

Jointly funded by the Department for the Economy (DfE) and DAERA as part of a Small Business Research Initiative (SBRI), the first phase of the project saw six NI companies awarded £100,000 each to develop sustainable solutions for slurry.

The pilot projects have focused on separation of slurry on farms, with the solid fraction used as a feedstock in anaerobic digestion (AD) plants to create renewable energy. The resultant digestate is then processed, with the P removed, which can then be sold as a bio-fertiliser or exported out of NI.

Explaining the concepts to MLAs on the Stormont Agriculture committee last Thursday, Jonathan McFerran from DAERA said estimates suggest NI has an annual surplus of 6,000t of P over and above that required to meet the needs of grass and other forages.

A key target is to reduce that excess by at least 1,000t annually by the end of year three of the project.

Equipment

The £10m of capital will be made available to support the funding of mobile equipment to separate slurry on farms and also for equipment to separate digestate once through the AD process.

McFerran maintained that there are multiple benefits to be realised from separating slurry on farms. The solid fraction going to AD contains most of the problem P. The remaining liquid fraction has most of the nitrogen, takes up less tank space and is easily spread using low-emission slurry spreading equipment.

But it is also necessary to process digestate at the end of the process. “If you’re just land spreading the digestate you have the same problem - the P is going back out on the land. You need to remove P from the digestate,” said McFerran. The longer-term vision is that a number of AD plant operators will come together to build a centralised digestate processing facility.

McFerran maintained that the feedback from farmers towards the project has generally been positive, but it remains unclear what value (or cost) might be placed on separated slurry for AD.

Cost model

“In the Netherlands farmers pay to get that [slurry] taken away. You imagine there would be some cost model, but that needs to be worked out,” he told MLAs.

DAERA hope to launch the second phase of the project in the coming weeks, with successful companies starting work this autumn. Only those companies who took part in phase 1 can apply for the second phase of funding.