ZeroNsile Red Clover farmers make plans for the 2025 season

The ZeroNsile on-farm research project, being delivered by AFBI and AgriSearch aims to examine the feasibility and practicalities of producing silage without the use of manufactured N fertiliser. The research project focus primarily on red clover-based silage swards.

One of the twelve farmers involved, Douglas McKenzie (Moy) recently hosted the project group to review sward performance and discuss management for the season ahead.

When the group met in February they reviewed the yield and quality results from the swards during the 2024 season.  The group have also committed to meeting up on a regular basis on each other’s farms during the 2025 growing season to share their experiences.

To kick start this, on 1 May Douglas McKenzie described his red clover management from reseeding in August 2023 to date and is very pleased overall with the performance of his red clover sward, the silage quality and the fertiliser N savings he has made. At this meeting, Dr David Patterson (AFBI Grassland Agronomist) lead a group discussion on aspects of establishment, weed control, cutting strategies and emphasised to the group that their swards are now in their second year when healthy stands of red clover will have huge potential for N fixation, without the need for chemical N.  This will reap financial rewards and reduce harmful nitrous oxide gas emissions due to the lower application of N fertiliser. He reminded the group that results from the 2024 establishment year showed that red clover swards compared favourably for yield and had similar quality to grass-only silage swards.

Silage yields and quality will be assessed over the 2025 season and compared to conventionally managed grass swards on the project farms.  Jason Rankin, Manager at AgriSearch added, “Research into lowering the use of artificial nitrogen is a priority of AgriSearch - not only does this offer the potential for farmers to save money on the purchase of fertiliser but it also helps to lower carbon emissions since and fertiliser use accounted for around 20% of GHG emissions across our Beacon Farm Network in Northern Ireland”.

Previous AgriSearch funded research at AFBI, Hillsborough showed that red clover has the potential to grow high yields of protein rich forage whilst only using cattle slurry as fertiliser. With this in mind, John Morrow (Agriculture Manager, AgriSearch) lead a workshop with the project farmers on nutrient management planning for the silage cutting season ahead, to maximise use of their slurry nutrients and supplement with chemical fertiliser when required.  He emphasised the phosphate and potash nutrients supplied from slurry and how to adjust the rate of application relative to their soil indices. The group also discussed sulphur, where deficiencies are seen by yellowing of the youngest leaves of grass, and how this can reduce N fixation by the clover. Two cuts of silage can remove 20-40 kg Sulphur/ha. Previous AFBI research showed that multi cut systems are at highest risk of Sulphur deficiency especially early in the season. Corrective fertiliser options were then discussed.

The farmers in the project are building their knowledge and experience of growing and utilising red clover on their farms - this project will help give farmers across Northern Ireland a better understanding of the potential and suitability of red clover for silage. Public farm walks are planned for the summer and details will be released soon on the AgriSearch website.

The ZeroNsile is an on-farm research project funded by AgriSearch with AFBI providing scientific and technical support.

Notes to editors: 

AFBI is an arms-length body of DAERA delivering research and development, diagnostic and analytical testing, emergency response capability and expert scientific advice for DAERA and other government departments, public bodies and commercial companies in Northern Ireland, and further afield.

AFBI’s Vision is “Scientific excellence delivering impactful and sustainable outcomes for society, economy and the natural environment”.

AFBI’s Purpose is to deliver trusted, independent research, statutory & surveillance science, and expert advice that addresses local and global challenges, informs government policy and industry decision making, and underpins a sustainable agri-food industry and the natural and marine environments.

AFBI’s strategic priorities:

• Leading improvements in the agri-food industry to enhance its sustainability;
• Protecting animal, plant and human health;
• Enhancing the natural and marine environment;
• Delivering quality outcomes and impact;
• Enabling world class science through excellence in people, places & technology.

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