Recovered Nitrogen from Manure
RENURE
Climaticus publishes this resource because RENURE is the regulatory and technical foundation on which viable AD projects in Ireland will increasingly depend. Understanding it is prerequisite to designing feedstock systems, digestate flows, and farm partnerships that work.
RENURE – REcovered Nitrogen from manURE – refers to fertilising products derived from processed livestock manure in which nutrients are recovered and transformed into forms that can substitute mineral fertilisers.1 The critical distinction is classification. Once digestate from an AD plant undergoes sufficient further processing, it is classified as a chemical fertiliser rather than organic manure – and does not count toward the 170 kg/ha organic nitrogen limit imposed by the Nitrates Directive.2
Under Directive (EU) 2026/288, adopted in February 2026, Member States may authorise an additional 80 kg N/ha per year through RENURE fertilisers, subject to technical requirements and environmental safeguards.3 Qualifying processing routes include mineral concentrates from ultrafiltration and reverse osmosis, and ammonium salts from ammonia stripping and scrubbing.4
Why It Matters for Irish Farmers
Ireland produces more organic nitrogen than its land can legally absorb. The Nitrates Directive caps manure application at 170 kg N/ha per year in Nitrate Vulnerable Zones. For a primarily grass-based, high-stocking dairy sector already operating at or near that ceiling, this is a commercial and environmental constraint with no straightforward resolution under current rules.
A farmer who exports slurry to an AD plant cannot bring the resulting digestate back to their own farm if they are already at the organic nitrogen ceiling. This forces the purchase of chemical fertiliser to replace lost nutrients, breaking the circular nutrient cycle and increasing costs.5 RENURE closes that loop. Farmers can export slurry off-farm and re-import the processed constituent nitrogen in separated liquid form. Phosphorus and potassium fractions can be spread separately and in a far more targeted way, reducing organic nitrogen on holdings while substituting chemical fertilisers.6
Replacing one tonne of artificial fertiliser with digestate saves approximately one tonne of oil, 108 tonnes of water, and seven tonnes of CO₂.7
1 tonne
of artificial fertiliser replaced saves ≈ 1 t oil, 108 t water, and 7 t CO₂.⁷
Up to 66%
reduction in ammonia emissions through RENURE application combined with emission-reducing techniques.¹²
Comparable
nitrate residues after RENURE application vs synthetic mineral fertiliser – no elevation of leaching risk.¹³
The Connection to Anaerobic Digestion
To be classified as RENURE, digestate must be further processed – by ammonia stripping, membrane filtration, or chemical precipitation – to produce ammonium salts, mineral concentrates, or struvite. These processes make the nitrogen in digestate more plant-available and functionally equivalent to chemical fertiliser.8
Digestate from agri feedstock is a relatively uniform product and can be separated into nitrogen, phosphorus, and potassium fractions using existing separation technology.9 RENURE and biomethane infrastructure are inseparable propositions.
Stage 1
Raw Slurry
Untreated livestock manure. Counts fully toward the 170 kg N/ha limit. Higher odour and ammonia volatilisation risk at application.
Stage 2
Digestate
Output of anaerobic digestion. More stable than raw slurry and infiltrates soil faster, reducing volatilisation risk. Still classified as organic manure under current rules.
Stage 3
RENURE Products
Further processed digestate: mineral concentrates or ammonium salts. Recognised as a fertilising product. Up to 80 kg N/ha permitted above the organic nitrogen limit.
Environmental and Odour Performance
Research published in the Science of the Total Environment demonstrates that anaerobic digestion decreases odour activity values after field application relative to untreated cattle manure.10 IEA Bioenergy process analysis confirms that the AD process reduces odour emissions, and that the superior infiltration speed of digestate into soil lowers the risk of excess ammonia volatilisation when handled according to best agricultural practice.11
Field trials across EU member states indicate ammonia reductions of up to 66% through RENURE application in combination with emission-reducing techniques, and nitrate residues following RENURE application are generally comparable to those measured after synthetic mineral fertiliser – indicating no elevation of leaching risk.12,13
The Regulatory Position in Ireland
The February 2026 amendment to the Nitrates Directive, when implemented, will allow Ireland to authorise the application of processed manure fertilisers above the 170 kg N/ha limit, subject to compliance with specifications and parameters designed to ensure no adverse impact on water quality or the environment.14Ireland must transpose the directive into national law by 2 March 2028.
Teagasc identifies ISO accreditation as the decisive quality-control step, noting that this accreditation changes the status of RENURE from a waste-based organic manure product to a recognised fertiliser product.15
Footnotes & References
- European Commission, Directive (EU) 2026/288, February 2026.
- European Commission, Council Directive 91/676/EEC (Nitrates Directive), as amended.
- European Commission, Directive (EU) 2026/288, op. cit.
- Themis Industries, Nitrates Directive: New Guidelines for RENURE Fertilizers, March 2026.
- Teagasc, RENURE: A New Opportunity for Irish Dairy Farmers Facing Nitrates Limits, January 2026.
- Irish Co-operative Organisation Society (ICOS), ICOS Welcomes Commission Draft Paper on RENURE, May 2024.
- Irish Farmers Journal, New Rules to Reduce Unintended AD Consequences, November 2025.
- Agriland, Explainer: How Will RENURE Help Dairy Farmers on Nitrates Limits?, January 2026.
- ICOS, op. cit.
- Lemes et al., Effect of Anaerobic Digestion on Odor and Ammonia Emission from Land-Applied Cattle Manure, Science of the Total Environment, 2023.
- Drosg, Fuchs et al., Nutrient Recovery by Biogas Digestate Processing, IEA Bioenergy, 2015.
- British Agriculture Bureau, RENURE: A Practical Solution that Supports a Circular Economy, February 2026.
- Open Access Government, How RENURE is Shaping Sustainable Nitrogen Management in the EU, May 2026.
- Philip Lee LLP, Accelerating Infrastructure: Ireland's Economic Priorities, April 2026.
- Teagasc, RENURE: A New Opportunity for Irish Dairy Farmers Facing Nitrates Limits, op. cit.
RENURE in the Climaticus Ecosystem
RENURE is not a standalone product. It sits inside the same infrastructure Climaticus develops for biomethane, feedstock systems, and circular bioeconomy projects. Processing manure into a recognised fertilising product only makes sense when the AD plant, the feedstock contracts, the digestate flows, and the farm partnerships around them are designed together.
Talk to Us About RENURE
Tell us about your farm, your digestate stream, or the RENURE opportunity you are exploring. We will respond with a clear next step.