Opinion: Latest EPA water-quality report disappointing; but on-farm solutions exist

By Dr. Daire Ó hUallacháin, Dr. David Wall and Dr. Karl Richards of Teagasc

The results from the latest Environmental Protection Agency (EPA) Water Quality in Ireland 2013-2018 report are disappointing.

The report highlights that 52.8% of surface waterbodies are at good or high status, down from the 55.4% recorded for the 2010-2015 period.

The negative trend is driven largely by a decline in the quality of some rivers, and overshadows some of the improvements in quality for other waterbodies (i.e. groundwater, lakes, coastal and transitional/ estuaries).

Although overall water quality in Ireland compares favourably to the EU average (40%), meeting objectives under the Water Framework Directive, whereby all waterbodies achieve good status by 2027, will be challenging.

In this report a number of pressures on water quality have been identified including: agriculture, hydromorphology (i.e. changes to the physical condition of waterways); urban; and domestic wastewater and forestry.

With over 65% of the land area dedicated to agriculture and watercourses neighbouring on almost three quarters of farms, it’s not surprising that agriculture has an influence on water quality.

The EPA report highlights the importance of targeting actions to where they are most effective to reduce sources of nutrients – for nitrogen (N) in particular – and breaking the pathway between phosphorus (P) and sediment sources and rivers, in particular.

Farmers are familiar with the various compulsory and optional actions implemented under the Good Agricultural and Environmental Conditions regulations, the Nitrates Action Programme and through the Green, Low-Carbon, Agri-Environment Scheme (GLAS) that aim to either reduce sources of nutrients or break the pathway between sources and rivers.

The EPA report specifically highlights increases in N loads in rivers and calls for reduced chemical N fertiliser use and improved N use efficiency.

Reducing chemical N fertiliser use on farms, while maintaining grass and crop yields, can reduce losses to water and also reduce greenhouse gas (GHG) emissions, as highlighted in the recent National Climate Action Plan.

Management options

Ongoing and new Teagasc research and advice is exploring numerous sustainable management options and actions than could be employed on farms to further increase the efficiency of nutrients.

Farmers can improve N use efficiency by optimising soil fertility, by applying lime to correct soil pH and targeting slurry and compound fertilisers to fields with low soil P and potassium (K), which leads to a reduction in N fertiliser requirements.

The Teagasc NMP online tool provides tailor-made nutrient management advice and detailed field-by-field fertiliser plans for farmers.

Improving synchronisation of N fertiliser applications and grass requirements is key and reducing fertiliser applications when grass growth is low, especially on cold and wet soils in springtime.

Chemical N fertiliser can be further reduced through the use of low-emission slurry spreading.

Additionally, Teagasc research has shown that N fertiliser use can be reduced (by up to 50%) on clover/grass and multispecies swards, with no reduction in yield.

In relation to breaking the pathway of nutrient and sediment delivery to rivers, the Teagasc-led SMARTER_BufferZ project is exploring optimal approaches for ensuring that the right actions are targeted to the right place.

Localised areas within the landscape of highest risk for nutrient loss can be identified using LiDAR technology to target actions areas where they will be most cost-effective.

Recent Teagasc research has highlighted that sediment, rather than nutrients, plays a much larger role in impacting the ecology of streams and rivers. Sources of sediment can include riverbanks, roads, and forestry, along with agricultural sources.

Changes in climatic patterns are also likely to influence water quality. Drought conditions and prolonged periods of sunshine (as witnessed in 2018), not only influence the quality of freshwater ecosystems, but also soil conditions resulting in increased N availability.

More frequent episodic high rainfall events can also remobilise sediment in river beds resulting in damage to sensitive freshwater ecosystems.

Latest advice

More encouragingly, the recent water quality report also highlights a marked improvement of 16% in the water quality in the Areas for Action catchments, where 30 water-quality advisors from the Agricultural Sustainable Support and Advisory Programme (ASSAP) are targeted.

Under this programme, these water quality advisors work closely with local authorities, the farming community and other stakeholders to identify where improvements in water quality could be attained.

Similarly, a collaborative, multiple stakeholders targeted approach is also being rolled out in various high-status river catchments within the KerryLIFE, DuHallowLIFE projects and European Innovative Partnerships (EIPs) – such as the Freshwater Pearl Mussel Programme.

These projects ensure that participating farmers and landowners are provided with the latest advice on reducing sources of nutrients or sediment, and incentivised to undertake specific, targeted actions to break the pathway between source and watercourse.

The above article was written by: Dr. Daire Ó hUallacháin, Teagasc senior research officer, ecology and water quality; Dr. David Wall, Teagasc senior research officer, soil science; and Dr. Karl Richards, head of the Teagasc environment research department, Johnstown Castle.