For many farmers, the Agricultural Catchments Programme came into focus recently, when the the nitrates derogation cut came sharply into focus and the Timoleague catchment rose to prominence.
Timoleague is one of six water catchments in the country at the centre of the Agricultural Catchments Programme (ACP).
Speaking at last week’s Catchment Science 2023 conference, Professor Frank O’Mara set out both the purpose and the importance of the programme.
The science behind it all
Simply put, the ACP provides the science for the policy review of Ireland’s Nitrates Action Programme and the nitrates derogation, by conducting research across all soil types and land uses.
There are 23 researchers, advisers, technologists and technicians in the ACP team, combining research with advice and knowledge transfer to farmers.
A water catchment is an area around a river, lake or other water body and the ACP monitors six smallscale water catchments, ranging in size from 3km2 to 21km2.
They are Timoleague in Cork, Dunleer in Louth, Cregduff in Mayo, Corduff-Sreenty in Monaghan, and Castledockrell and Ballycanew, both in Wexford.
The catchments were chosen to be representative of intensively managed agricultural land on different soil types and agricultural land use, covering different levels of risk for nitrogen and phosphorus loss.
Since 2008, the same experiment has been carried out in each catchment, providing data every 10 minutes, 365 days per year for the past 15 years.
It has over 800,00 records of water discharge, phosphorus, nitrate-N, temperature, conductivity, pH and turbidity (clarity).
There are 300 farmers in the six catchments and they work closely with the ACP’s four agricultural advisers
Other measurements are also repeated across each catchment, such as soil chemistry, river snapshot monthly samples, groundwater sampling, ecological surveying, National Farm Survey data recording, CO2 fluxes in four catchments and ammonia emissions in two catchments.
There are 300 farmers in the six catchments and they work closely with the ACP’s four agricultural advisers, who provide both specialist water advice and general agricultural advice to the farmers.
These four advisers – Mark Boland, Suzanne Neary, Kevin Madden and Oisin Coakley – along with the agricultural catchment specialist, Eddie Burgess, also disseminate the findings from the programme to a wider agricultural audience.
This happens through training of other Teagasc staff, regular hosting of farm discussion group visits and training of farmers for nitrates derogation and other environmental schemes.
Professor Frank O’Mara summarised the key findings from the ACP at Catchment Science 2023 while speaking to the Irish Farmers Journal. These include:
1 The underlying soil type and geology of a catchment can override the effect of nutrient source pressures. The ACP found there was no clear link between stream nitrogen (N) and phosphorus (P) concentrations and nutrient loading at small catchments scale. “The message from that is that targeted and efficient mitigation measures are required,” Professor O’Mara said.
2 Long-term weather shifts and short-term weather extremes need consideration and may require different mitigation strategies and real-time advice to farmers/landowners. “That’s very important from the point of view of monitoring the effectiveness of [water quality] measures that might be put in place, you know, looking [at results]; going year to year can be overridden by the effects of weather shifts,” pointed out Prof O’Mara.
3 Airborne lidar surveying produced information on pathways and delivery sites that can facilitate targeted and efficient mitigation measures and can be upscaled to larger areas.
4 Following heavy rainfall, stream phosphorus (P) concentrations were gradually reduced during the closed period, and did not increase in the four-week period after the end of closed period.
5 Most of the sediment losses came from stream bank/bed erosion and road losses on the more common land uses. Soil permeability largely influenced the sediment loss.
6 Knowledge exchange is required for effective nutrient management planning.