Improving Ireland's water quality a 'core requirement' for Irish farmers
Blackwater Or Of Picture: Maccarthy River Bodies Status Currently Good In Near Has Island, High Co Munster 66% The Lismore, Surface River With Waterford Bushe's Water The Blackwater Dan Catchment
Readings from Munster Blackwater monitoring stations made the water quality problem clear for farmers at the recent Teagasc National Dairy Conference.
At Lismore bridge, measurements in 2023 indicated that phosphate pollution decreased from 2007 to 2023, to less than the national average levels in 2023. The phosphate concentrations at Lismore bridge are almost low enough to support high water quality status. However, nitrogen levels were higher than that required to support good water quality, and there was no indication of any 2007 to 2023 reduction.
At Tallow bridge, phosphate had also reduced to levels in 2023 less than the national average. Nitrogen was higher than that required to support good water quality, but there were indications of a 2007 to 2023 reduction.
Phosphate in the water at Kilcummer bridge (located about 2.7km by road south of Castletownroche) was low in 2023, less than the national average, but with indications that concentrations increased somewhat since 2007. Nitrogen levels were higher than that required to support good water quality, but with indications of a 2007 to 2023 reduction.
At the monitoring station upstream from the Funshion-Blackwater confluence, phosphate levels reduced significantly since 2007 to less than the national average in 2023, when the level of concentration was almost low enough to support high water quality status. Nitrogen levels were higher than that required to support good water quality, but with indications of a reduction over the 2007 to 2023 period.
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Professor Pat Dillon, Director of Research in Teagasc, told the conference that all sectors of Irish agriculture must work to improve Ireland’s water quality status. He said it is a “core requirement” for the communities in which we live and farm, for marketing Irish agri-food produce, and for retention of Ireland’s Nitrates Derogation.
“The main pressures affecting water quality are agriculture, which is not surprising given we are the largest user of land, followed by hydromorphology, urban waste water and forestry.
“Agriculture is a significant pressure in 1,023 of the 1,649 water bodies that the EPA has identified as being ‘at risk’ to water quality, but two-thirds of these also have other significant pressures.
The EPA assesses biology, physio-chemistry, and hydromorphology. For high or good status, a waterbody must score favourably under all three. The two big physio-chemistry water quality indicators are phosphorus and nitrogen. Professor Dillon noted: “During 2021-2023, 27% of Irish rivers had unsatisfactory phosphate concentrations. Phosphorus is really associated with heavy soils more than free-draining soils. It is associated with overland flow of soil containing phosphorus into water.
“During 2021-2023, 42% of Irish rivers had nitrate concentrations over 1.8 mg/l, the level the EPA use to indicate good water quality. Nitrates really is a south, south-east issue, and it’s a problem across free-draining soils where nitrate is directly leached out of the soil.”
In general, reduced surface water status in recent years can be related to the severe drought in 2018 causing a significantly increased nitrogen (N) surplus on farms. Farmers have acted to improve water quality by reducing fertiliser applications and altering dairy cow supplementation to reduce nitrogen excreted through urine.
Professor Dillon advised dairy farmers to study Pollution Impact Potential (PIP) maps for their area. Farmers could further improve water quality by increasing their slurry storage, reducing nutrient losses from yards and roadways, growing over-winter cover crops on tillage farms, and efficiently using pig and poultry manures.
To reduce point source pollution from farmyards and roadways, farmers should ensure gutters and downpipes are in good working order, with rainwater piped away to a clean soakaway area. Clean water should be diverted away from yards or concrete areas to prevent the production of dirty or soiled water. Farm traffic should be restricted to certain parts of the yard, and the soiled yard area reduced by regular cleaning.
Just over half of Irish surface water bodies (rivers, lakes, estuaries and coastal waters) achieved at least good status in the latest EPA Water Quality in Ireland report, with the primary challenge being too much P and N.
The Slaney, Barrow-Nore, Suir, Blackwater, Lee-Bandon, and Boyne catchments have been prioritised for an 8-Actions for Change campaign. Their ecological status varies from 67% in the high or good status for the Bandon-Ilen catchment to 32% for the Boyne. The Munster Blackwater River Catchment currently has 66% of surface water bodies with high or good status.
In 2021, the EPA calculated the reductions in N load required in 18 major river catchments. The reduction varied from 1% in the Lee to 53% in the Barrow. The EPA is currently updating this report, with indications that the load reductions needed in the Slaney and Barrow are not as great as first indicated.
Since 2020, the application rate of N, P and K across all farms reduced by 21%, 25%, and 22%, respectively, according to Teagasc.
