Earlier this week, Teagasc conducted a sustainability/clover farm walk on the farm of John and Brenden Walsh in Ballylooby, Co. Tipperary.
The walk focused on the measures introduced by the Walshes to make their farm more sustainable and to reduce the reliance on chemical fertiliser.
154 predominately Friesian cows are milked on the farm, with replacements and some beef stock kept on out-farms.
The farm has been able to reduce its emissions to 0.64kg carbon dioxide equivalent (CO2e) per kg of fat and protein corrected milk (FPCM), from 0.77kgCO2e/kgFPCM.
This is below the Dairygold co-op target of 0.75kgCO2e/kgFPCM.
The farm’s biodiversity figure is 14%, however an area of forestry which would increase this figure was not included.
There has also been 250m of hedgerow planted in recent years, with more planting planned in the near future.
Soil fertility
Improving and maintaining soil fertility has been a major focus on the farm, with soil sampling taking place on a yearly basis.
It was noted at the event that soil compaction could potentially be a limiting factor on many Irish dairy farms moving forward.
This has allowed the Walshes to achieve a pH of 6.2 on 85% of the farm, index 3 for phosphorus (P) on 85% of the farm, and index 3 for potassium (K) or above on 75% of the farm.
These improvements have meant that the maximum benefit can be gained from the chemical nitrogen (N) spread on the farm and has also made incorporating clover much easier.
Grass measuring also plays a key role on the farm, with Brendan completing 54 walks/year in 2021.
He said this has improved cow performance and that they never know where the cows are going next until a grass walk has been completed.
Clover
John and Brendan have increased the amount of clover in their swards, with 63% of the farm now having clover.
Speaking at the walk, John said: “Soil fertility is the key to making clover a success on farms.”
The majority of the clover on the farm has been incorporated using full reseeding, rather than over-sowing.
Over-sowing has been tried on the farm, with some mixed results achieved.
John said that to ensure the establishment of clover in swards is a success, it is important that it is “grazed at the right time – hail, rain or snow”.
“At week five, you apply the post-emergence and then in week six you graze it, no matter what the cover is,” he said.
“Last year we went into a paddock in June and then were only in there for four hours, but I had to be back in there again within 14 days.”
John added that they are aiming to reach a figure of 70% of the farm having clover and he believes that a higher clover content would be hard to achieve.
This is because the clover content in older swards will decline and there should be ongoing reincorporation of clover into swards.
The increased clover into the swards has meant that chemical N usage has been reduced to 135kg of N/ha over the entire farm.
Red clover has also been incorporated in the silage swards, which has further reduced the need for chemical fertilisers.
NUE
Nitrogen use efficiency (NUE) has increased further on the farm from 35% to an estimated level of 41% in 2022.
Last year 165kg of N/ha was spread across the whole farm and this was reduced to 135kg of N/ha in 2022.
Almost all the fertiliser spread on the farm was protected urea, with a small amount of compound fertiliser spread on clover swards.
Brendan stated that he avoids spreading fertiliser in heavily trafficked areas such as water troughs and entrances to paddocks.
He added that the use of a GPS fertiliser-spreading system has massivly improved the farm too, as it has helped to avoid overlapping or doubling up.
This has in turn, resulted in less fertiliser being spread on paddocks than previously has been.
Another factor in NUE is the produce sold off the farm, with 525kg of milk solids sold off the farm from 830kg of concentrates in 2022.
Breeding
The herd’s fertility performance is excellent, boasting a 90% six-week calving rate and an average herd economic breeding index (EBI) of €184.
Male dairy calves were reared on the farm and reared to beef, but the Walshes have now moved to using sexed semen and beef sires.
“The reason for using sexed semen is to get better heifers from our better animals, we are then breeding less dairy beef bulls and increasing the amount of high-value beef calves from the herd,” Brendan said.
This year, 50% of the cows are in-calf to beef sires, with breeds such as Aubrac, Saler, Angus, Hereford and Belgian Blue.
This, along with the other measures introduced onto the farm, has led to the decrease in kgCO2e/kgFPCM.