As part of a series of clover walks aimed at promoting clover use, Teagasc got things going by holding the first of 12 walks last week in Moorepark, Co Cork.

However, the talk wasn’t only about clover.

The tough weather conditions and its impact on dairy farmers took centre stage, highlighting the broader challenges farmers are dealing with right now.

Some of the 100 or so farmers in attendance said their cows haven’t seen grass since late September. Others said they have all their dry land grazed and were uncertain whether to start the second rotation.

Teagasc researcher Micheal O’Donovan said that farmers must deal with the reality of the situation on their own farm.

“We probably have a diverse group of farmers here, each with their own soil types to consider.

“However, on most farms, there’s usually some area where opportunities exist in getting cows out.

“So, my advice is to identify those areas and begin there, even if it’s just for a few hours a day. One hour of grazing in a 100-cow herd will save you one bale of silage,” he said.

For the farmers who are on the verge of starting their second rotation, Michael said when to start depends on how much grass is available.

“When to start really depends on how much grass is available on the first paddocks grazed. Ideally, these should be around 1,200kg DM/ha when grazed. The other considerations are to do with average farm cover and herd demand for grass.

Cows grazing grass and clover swards are produced 6,000 litres of milk.

“The average farm cover should not drop below 500kg/ha – if it does, growth rates will be impacted.”

He said the dry matter of the second round grass will only be 13% in wet weather but that first round grass will have a slightly higher dry matter of 15%.

As the group walked to the first board of the day, it was clear to see that the grass was slightly soiled and the post-grazing residual was far from ideal – not what one would expect to see at Moorepark.

Clover researcher Áine Murray said the cows had been grazing the field about a week previous.

She said that good cleanouts are extremely hard, even on the driest of land, but said that farmers shouldn’t worry as these can be corrected in the second rotation provided the weather improves.

One farmer questioned the researchers about poaching of the soil as he was heading into his second rotation. It was stressed at the walk that if a paddock was poached badly in the first rotation and is subsequently poached further in the second rotation, the paddock will see a big reduction in subsequent growth.

Michael O’Donovan said this could be a 30% reduction in yield for the year.

On poaching, researcher Michael Egan said that if a paddock has been badly poached in the first round, farmers should try get it spread with slurry or compound fertiliser containing phosphorus and potash to help improve soil structure and promote tillering of the grass.

If the weather dries up next week, I’d be saying you should be going with some fertiliser aiming to cut around 20 May

Another farmer raised a question about silage ground, saying he has fields earmarked for early cutting .They are yellow at the base and have not received nitrogen yet and he is wondering what to do.

Cutting date

Egan said: “Firstly, you need to decide your cutting date. At this stage, it’s too late to get it grazed by cows or young stock and too late to apply slurry to it, as you’ll have contaminated silage.

“If the weather dries up next week, I’d be saying you should be going with some fertiliser aiming to cut around 20 May.”

He went on to say that he’s heard that farmers might be planning to bulk up their first cut, as the pit is looking empty, which would push the cutting date out into June. But that’s a mistake as you’ll be missing the end of May growth rates and inevitably leading to a very late second cut.

April and early May are the best times for oversowing clover into established swards.

Clover trial

Researcher Áine Murray is running the clover trials at Moorepark. Áine is conducting a grazing trial using three groups of cows. The first group of cows is grazing a grass-only sward getting 200kg N/ha, the second group is grazing a grass and clover sward that is getting 150kg N/ha and the final group of cows is grazing a grass and clover sward getting 100kg N/ha. Each treatment group grew over 14 tonnes of grass in 2023.

“Cows grazing the grass and clover with an average clover content of 19% are producing 40kg more milk solids per cow than cows grazing a grass-only sward. This is equating to an extra €480/ha net profit.

“The difference is coming from the increase in milk yield rather an increase in the fat and protein composition. This is down to the increased feed intake of the cows on grass and clover swards,” she said.

Cows grazing grass and clover swards are produced 6,000 litres of milk whereas cows grazing grass only swards produced just shy of 5,700 litres of milk.

Both groups were fed the same level on concentrate at 580kg per cow and got 416kg DM of silage throughout the 2023 season.

Oversowing

While the clover trial results are excellent, the weather was the main topic of concern on most farmers’ minds at the walk.

However, with high pressure expected to come towards the middle of the month, the researchers encouraged farmers not to miss the opportunity to get clover established on their farms.

Michael Egan said that April is the best month for oversowing, but given the wet spring so far, May is likely to be a suitable month also.

Tips for oversowing clover

1 Pick a field with good soil fertility as clover has a high requirement for good soil fertility, particularly pH. The ideal pH for clover is 6.5. Choose a field with good grass varieties that is unlikely to be reseeded in the short term. Weed control should be corrected in the year prior to oversowing.

2 The best time to oversow is April or early May and because this coincides with an already busy time of year, farmers need to be prepared for oversowing now, even if the weather and ground conditions are currently unsuitable. Have the seed in stock and decide on what method to use and when to do it.

3 The key thing when oversowing is to ensure seed-to-soil contact. Tight grazing immediately before oversowing will open up the sward. Different methods are available and each are successful provided the conditions are right.

4 If broadcasting clover seed, mix the clover seed with 0:7:30 fertiliser and only add white clover to the spreader when you are in the field to avoid white clover settling at the base of the spreader, with a maximum area of two to three acres covered at a time. Spreading soiled water with a splash plate after sowing will improve seed to soil contact.

5 Oversow at a rate of 2.5kg clover seed per acre. Full reseeds should contain between 1.5kg and 2kg of clover per acre.

6 A key step is to ensure light to the base of the sward at all times to avoid the clover seedling getting shade out. This means the sward should be grazed regularly at low covers of 800kg to 1,000kg DM/ha.

7 Reduce nitrogen in the oversown sward for two months after sowing, but there should be no big reduction in nitrogen use until eight to 12 months after sowing.