As part of our ongoing series of updates from Teagasc research farms, we caught up with Eoin McCormack at Clonakilty to get the latest on their nitrogen strategies, clover management, cow performance and the challenges faced with this year’s reseeds.
Nitrogen Strategies
Clonakilty is currently between nitrogen trials, following the conclusion of a three-year experiment led by Megan Bock. While a new trial is being designed, the farm continues to replicate the previous trial’s blueprint to maintain consistency for ongoing water quality monitoring.
Current Nitrogen Treatments
- Grass Only, 150 kg N/ha
- Grass Only, 225 kg N/ha
- Grass-Clover, 150 kg N/ha
- Grass-Clover, 75 kg N/ha
Protected urea, 46% N, remains the fertiliser of choice, with application rates tailored to each treatment. For example, for the current rotation, the Grass Only 225 kg N/ha treatment receives 61 kg/ha of protected urea per application, while the Grass-Clover 75 kg N/ha receives 20 kg/ha of protected urea. On the general farm, nitrogen use is more flexible, with rates pulled back where clover content is sufficient.
Multi-Species Swards
Demonstration plots include grass only zero nitrogen and multi-species swards. The latter, now in its third year, has seen chicory fade out and plantain decline, but remains a valuable teaching resource for students.
Silage
Ground closed for second-cut silage has received 175kg/ha of protected urea, equivalent to 64 unit/ac of N, with the balance of the N coming from slurry spread at 2,500 gallons/ac.
Grass and Clover Cow Performance
Despite the variation in nitrogen inputs and sward composition, milk yields across the different groups remain close.
Milk Performance
| Group | Grass Only 150 | Grass Only 225 | Grass-Clover 150 | Grass-Clover 75 |
| Yield (l) | 21.0 | 22.6 | 22.8 | 23.5 |
| Milk Solids (kg) | 1.83 | 1.94 | 1.94 | 1.97 |
| Fat % | 5.15 | 5.00 | 4.85 | 4.69 |
| Protein % | 3.62 | 3.65 | 3.75 | 3.73 |
| Concentrates (kg) | 3 | 3 | 3 | 3 |
Good grass growth and utilisation is being recorded, with average farm covers ranging from 671 to 717 kg DM/ha and growth rates between 82 and 98 kg DM/ha/day. Stocking rates are consistent at 3.24 LU/ha across all groups.
Key grass performance metrics
| Metric | Grass Only 150 | Grass Only 225 | Grass-Clover 150 | Grass-Clover 75 |
| AFC | 671 | 717 | 683 | 704 |
| Cover/LU | 207 | 221 | 211 | 217 |
| GR | 82 | 94 | 90 | 98 |
| Demand | 52 | 52 | 52 | 52 |
| SR (LU/Ha) | 3.24 | 3.24 | 3.24 | 3.24 |
Clover Varieties
Clonakilty’s clover strategy has evolved over the years. After trialling several varieties, Chieftain and Crusader have become the most commonly used due to their reliability and leaf size. Recent reseeds and overseeding have introduced Dungloe and Clodagh.
2025 Reseed Mix
- Astonconqueror (3 kg)
- AstonEnergy (3.5 kg)
- Glenfield (4 kg)
- Clodagh (0.75 kg)
- Dungloe (0.75 kg)
2025 Reseeds
This year’s reseeds have faced significant challenges. Sown during a dry spell, germination was delayed, resulting in patchy establishment and slow growth. Weeds have outgrown grass in some areas. Eoin estimates that the reseeds are around two weeks behind where they should be, and the team is closely monitoring progress.
Timeline
- Sprayed off: 16th April
- Ploughed: Week of 28th April
- Seeded: Week of 12th May
Breeding Update
75 cows were scanned last week, these had been served over 32 days.
- 5 were not in calf
- 4 received a prostaglandin shot
- 1 cow with a follicle will be monitored for heat, with a recheck planned if needed
Moorepark Open Day 2025
More detailed information on the Teagasc research farms will be discussed at the Moorepark Open Day 2025 on Wednesday, July 2. Find out more about the Moorepark Open Day 2025 here.