Last week’s Irish Grassland Association (IGA) summer dairy tour was an online affair held on two farms 300km apart. The focus was on clover and the tour visited Kevin Moran in Galway, a young farmer who started his clover journey properly in 2020 and John Joe O’Sullivan in west Cork who has been farming with clover all of his life.

The Irish Farmers Journal visited the O’Sullivan farm where John Joe farms with his son, Andrew, at Rosscarbery, a few miles in from the coast. Their farm extends to 100 acres in one block and they are milking 69 and rearing replacement heifers and growing all winter feed.

The overall stocking rate is 2.35 livestock units per hectare.

No stranger to success, John Joe has won numerous milk quality awards over the years and won the Protein 350 competition in 1999.

Clover has always been a big part of the farm at Rosscarbery and not only because of the benefits to pasture growth and cow performance.

John Joe has been a beekeeper since 1979 and currently has five hives of bees. The nectar that the bees gather is primarily from clover and bramble or briars, which gives it a distinctive flavour. The honey is sold and brings in an extra income stream to the farm but it also brings other benefits.

“You’re tied to nature, every time you go for the cows you see what the bees are going to be working on today. You’ll see the plants along the fences [hedgerows]. On our farm here all of the original, or most of the original, fences are on the farm and there’s a lot of flora and biodiversity around,” John Joe says.

Last year, the herd delivered 482kg MS/cow to Lisavaird Co-op and the O’Sullivans are on track to do over 500kg MS/cow this year from between 500kg and 600kg of meal per cow.

The EBI of the herd is €151 and John Joe says when he’s picking bulls he’s looking for bulls that are a plus in fat and protein and have good temperament. All the cows are black and white and John Joe hasn’t done any crossbreeding.

The best field of clover on the O'Sullivan farm.

About 30% of the farm is at optimum levels of clover (above 25% to 30% clover content) but there is clover present in nearly all other paddocks at varying levels.

The O’Sullivans’ goal over the next few years is to get all paddocks up to optimum levels and then cut back on chemical nitrogen further and get a greater benefit in milk production. Last year, they spread 152kg N/ha across the farm and this is something they would like to reduce further.

Despite having a considerable amount of clover on the farm, soil fertility is far from optimum.

While soil pH is at a good level, over 90% of the farm is at soil index one and two for phosphorus (P) and over 80% is at soil index one and two for potash (K).

This level of soil fertility seems counter-productive to having good clover levels but the O’Sullivans are possibly overcoming this by drip feeding P and K on to the grazing paddocks throughout the grazing season.

There are six months of slurry storage on the farm and they have their own slurry spreader with dribble bar, meaning they can spread soiled water and slurry throughout the summer months, as well as spreading 18:6:12.


However, John Joe says he wouldn’t compromise on soil pH as he previously oversowed clover on land with low pH and the success rate was very poor. The farm is being soil-sampled every three years and fields that are low in P and K are targeted with slurry.


There are two ways of establishing clover on the farm. The first is through a full reseed and, secondly, through over sowing.

Traditionally, when reseeding a field, a fodder crop would have been sown the previous autumn and grazed with weanlings over the winter before being one-passed with grass and clover seed the next spring.

John Joe says it’s essential that the clover seed is not buried when sowing. He asks his contractor to lift the tines at the back of the sower so the seeds are just left sitting on the ground before being rolled in.

John Joe O'Sullivan speaking to Mark Treacy at the Irish Grassland Association event

About 10 acres are over-sown with clover per year, usually after a cut of silage is taken in early May. Andrew spreads 2.5kg/acre of unpelleted clover seed using the quad and the fertiliser spreader, sowing just clover.

The shutter on the fertiliser spreader is fully closed but with age and wear, there is still room for the clover seed to come out and the rate is just right.

Soiled water is spread after sowing and the field is grazed at light covers for the rest of the summer and no more chemical fertiliser is spread, just soiled water and slurry.

Any paddock with less than 15% clover is on the list for over-sowing, but John Joe is adamant that it’s a waste of time trying to get clover established if the soil pH is not right. He’s not as worried about P and K because, in his case, he can work on that while drip feeding it slurry, soiled water and 18:6:12.

At last week’s online event, John Joe was asked about bloat and if it was a problem on the farm.

“We’ve never had a problem with bloat. Even in my Dad’s time, it wasn’t a problem. I think what’s helping us is the fact that we’re on 12-hour breaks every day so cows have to graze down into the sward whereas if we were on full paddocks they could gorge themselves and get bloat.”

On maintaining clover in the sward, he says that getting silage cut early is important as it means the sward is cut clean and not lodged, giving the clover a good chance to take off after cutting.

Only one big first cut is made and the rest of the silage is got from surplus paddocks. Pre-grazing yield is usually around 1,200kg to 1,500kg/ha.

Any covers over 1,500kg/ha are usually skipped over and left for a week before being cut for bales. He says regular cutting helps the clover as it gives it an advantage over the grass after cutting.

Andrew returned home to farm in 2015 and went full-time two years ago. Over that time, cow numbers have increased to the current number of 69. With 100 acres available for grazing, I asked Andrew if he’s tempted to push cow numbers higher, but he says the current system is working for them and they’ve no reason to change.

Over-sowing experience: Kevin Moran

The IGA event also heard from Kevin Moran, who farms at Caherlistrane in Co Galway. He is milking 270 cows and is stocked at 2.89 cows/ha on the milking platform and grew 15.6t DM/ha last year from 219kgN/ha.

He is including clover in the reseeding programme, but also over-sowing clover to get the percentages of clover up. His long-term goal is to grow similar tonnages of grass as he is now, but with less nitrogen.

Kevin’s biggest lesson to date was around the timing of over-sowing and the area to be done at one time. Last year, he over-sowed over 30% of the farm in one go in July. He says this was far too much area to be done at once and was much too late in the year.

“From now on, I’ll only over-sow in April or May. I’ll do no more than 10% or 12% of the farm at any one time, so it’ll be easier to manage it after sowing. I’ll spread watery slurry or gran-lime on it and graze at low covers three, four or five times before moving on to do another part of the farm.”

He says establishing clover is going to become an annual expense on his farm;

“Even when I get clover established on all of the farm, it’ll still be an ongoing cost to keep it there. I see it as part of fertiliser costs. It is more unforgiving than fertiliser in terms of management, but it’s a big part of where we as dairy farmers need to go,” Kevin says.