David Fennelly

David Fennelly, Dairy Farmer, Laois

David Fennelly from Emo in County Laois is a full-time dairy farmer in partnership with his parents. As part of his Nuffield Scholarship, David will explore alternative, swards, inputs, and grazing strategies, which can provide solutions at the root cause of challenges facing pasture-based dairy farms. David’s farm has a strong focus on reducing environmental impact and it is also a demonstration farm for the Signpost programme, which aims to showcase science-based technologies to reduce Irish agricultural emissions. David is a 2020 graduate of University College Dublin with a Bachelor of Agricultural Science in Dairy Business. As a member of a discussion group, David also has an active role in local Macra na Feirme and GAA clubs.

Nuffield Study report is ‘Alternative pasture management to address the nitrates challenge at the root cause’

Executive Summary:

For millennia, dairy production has grown in Ireland based on our climate and natural ability to grow pasture. Our pasture-based system exists within our unique symbiosis of climate, land and water. Irish dairy is recognised globally as safe, nutritious, and environmentally favourable, with €6.42bn of exports in 2023. In the past decade, the sector has far surpassed the target of a 50% increase in national milk production as set out by Food Harvest 2020. Our latest agri-food sector strategy, Food Vision 2030, emphasises the requirement to build food systems with a neutral or positive impact on environment. For the dairy sector – this is now the greatest challenge. Growing and utilising grass underpins the competitiveness, profitability and sustainability of Ireland’s dairy production system. The aim for water quality is to achieve good or high ecological status in all water bodies. The main issue which impacts the quality of our waters, and their biological health is increased concentrations of nutrients, such as phosphorus and nitrogen. Agriculture and the natural nitrogen cycle are intrinsically linked, nitrogen being an important nutrient excreted by livestock and required for maximising grass production. Nitrogen in its nitrate state in soil, in excess quantities is at risk to be leached to water.

The aim of this study is to investigate grassland management practices which can deliver resilience in our farming systems, mitigating nitrogen loss to water while maintaining productivity of grass based dairy farms. The report sets out to look at the challenge from a root cause perspective.

Ultimately the soils under our management must carry out the function of filtering water while also carrying out the role of agricultural production. More extreme weather events, surplus nitrogen above the crop requirements in forms that can leach, and the movement of water through soil, are the basis of nitrogen loss to water from soils. In order to reduce the impact of grassland dairy production on water quality, it must be a key focus to reduce surplus nitrate above crop requirements and improve the water management capability of our soils.

Key findings of this study:

• Water movement, and soil nitrate concentration at the time of water movement, cause nitrate loss to water
• There is a strong correlation between nitrate leaching and farm nitrogen surplus. Farms with lower N surplus can be more profitable while having a lesser impact on nitrate leaching.
• Increased regulation alone will not minimise nitrate loss to water from dairy farms.
• Urine patches in a typical grazing system account for the 66% of the excretion of N from dairy farms and the most significant source of nitrate pressure on water – plantain in the grazing cow’s diet can reduce this significantly.

Key recommendations for stakeholders:

• A traffic light advisory system for nutrient application events. This should be a collaborative system engaging relevant stakeholders such as Met Eireann, Pasture base, and the EPA. This could be delivered via Dairy Co-operatives areas for increased accuracy and a means to offer advice to hard-to-reach farmers.
• Farmers should engage in continued professional development training in the area of soil management and the nitrogen cycle. Observational skills are required to assess and monitor soil function and a strong scientific knowledge is required to understand the N cycle.
• Nitrogen surplus as a new key performance indicator (KPI) – This KPI should be embraced by discussion groups. This is a positive setting whereby the top performers can help to improve the performance of the poorer performing farmers in this area.
• A heightened level of agronomy in pasture-based farming is necessary. This service could be provided to farmers by existing advisory bodies or private industry. This service has the capability to increase the efficiency of resources and data on farms and be a sound source of mentoring to help farmers in difficult growing seasons.
• The industry requires a more robust model of nutrient management planning at farm and regulatory level rather than whole farm stocking rate. This could capture more of the factors that are affecting nitrate leaching and reward the uptake of better practices.

Alternative pasture management to address the nitrates challenge at the root cause