Last month, the Assembly passed a motion on biomethane and digestion of manure as a solution to nutrient challenges.
It recognised manure and food waste as both environmental pressures and a potential sources of energy and nutrients and called for a cross-departmental biomethane and anaerobic digestion strategy.
Newton Emerson was unconvinced in his column (April 23), arguing “We can’t just recycle our slurry problem away”.
He is right to be sceptical of easy answers. But he is wrong to suggest significant manure recycling is neither possible nor desirable.
Northern Ireland faces a difficult phosphorus challenge. We have a substantial, invested farming sector producing high-quality food, but we operate with a significant, if debated, phosphorus surplus.
Meanwhile phosphorus remains essential. Phosphorous is a finite resource without substitute. Newton is correct that it cannot be destroyed: “it is an element”.
But that misses the point. It performs a specific and irreplaceable role in plant and human nutrition.
He also writes that “Europe is already polluted”. That is vastly oversimplified or wrong. Europe is not one field.
Some areas have nutrient surpluses, others have deficits. The EU remains heavily dependent on imported phosphorus fertiliser, largely from phosphate rock mines.
In 2024, EU countries imported around €3.97 billion of phosphorus fertilisers, with almost €1 billion worth coming from Russia.
None came from Northern Ireland’s manure. There are clear, unrealised, economic gains in capturing and redistributing agricultural nutrients for export.
On ammonia, BH Estates and the UK Centre for Ecology and Hydrology recently published Farm2Export: Ammonia, examining a manure-digestion supply chain.
We assessed the net effect on ammonia emissions nationally.
If farms holding 150,000 cattle, used 20 small scale AD plants to produce energy and feed a bio-based fertiliser facility we would deliver 12%, and potentially up to 30%, of DAERA’s national ammonia reduction target.
So the real policy question is not whether AD is good or bad, but what kind of system we incentivise. Poor design of the NIROC scheme missed the chance to require digesters to remove waste from existing rural businesses.
Now, in 2026, an opportunity exists to deploy new and existing AD infrastructure for better environmental and economic gain.
A badly designed system, with little manure input, poor storage and no nutrient plan, solves little. A properly designed one, using manures and wastes, producing biomethane, recovering nutrients, exporting surplus phosphorus and displacing imported fertiliser, is very different.
And simply reducing livestock is not a serious policy. Agri-food is a major employer, exporter and one of the few industries with real productive depth in rural areas.
Shrinking production without alternatives will export jobs and responsibility, weakening rural communities.
The challenge for the Executive is whether Northern Ireland can produce food with a lower nutrient footprint, stronger controls, better use of manure and more domestic renewable energy.
Pretending the only answer is less farming, less investment and more delay is not the way forward. The serious argument for AD is that it can, and does, stabilise and concentrate nutrients, and can enable significant reductions in pollution.
Adding the potential to reduce the cost of pollution to the export potential, and production of sizeable quantities of reliable, indigenous energy, this sector is economically and environmentally viable.
- Jack Blakiston Houston is managing director of BH Estates
