Farmers encouraged to plan for a second cut of silage

Farmers have been encouraged to plan for a second cut of silage in 2018 by Teagasc dairy specialist Dr. Joe Patton.

Improved grass growth and ground conditions has been witnessed in most parts of the country in recent weeks, with many farms taking the opportunity to begin harvesting first-cut silage.

The Teagasc Fodder Working Group is reportedly monitoring conditions across various sites nationally.

Commenting on the current situation, Dr. Patton said: “It’s important that the first cut is not delayed and that the majority of farmers plan for a second cut in the 2018 silage season.

Every effort should be made to rebuild fodder stocks during the coming months to ensure adequate stocks for the 2018 winter/2019 spring.

Noticeable trends

In relation to grass growth, the Teagasc dairy specialist noted that PastureBase data is reporting average daily growth rates of 70kg to 80kg Dry Matter (DM) per hectare.

Differences within a county are greater than between counties, reflecting individual farm management decisions, he added.

Overall, many farms are producing grass surpluses on grazing areas; these will likely need to be removed as baled silage to maintain grass quality, Dr. Patton said.

On areas closed for silage, DM yields have reportedly “increased considerably“.

Well-managed swards in Munster and south Leinster were at 4,500kg to 5,800kg DM/ha on areas grazed in late March, and 5,000kg to 6000kg DM/ha on areas closed since autumn, he claimed.

‘Quality targets should now dictate the cutting date’

With these yields in place, quality targets should now dictate the cutting date, according to Dr. Patton.

He warned that delaying the first cut for too long past the grass heading date will cause a large drop in quality and reduce second-cut yields significantly.

Farmers have been advised to aim to take out main first-cut areas by early June; while areas grazed twice this spring can be cut around 7-10 days later.

Meanwhile, the Teagasc dairy specialist stated that grass sugars are the main consideration for crop preservation.

Indications from various sites around the country are that sugars are ranging from 1.5% to 3.5%; the target for good preservation is at least 2.5% – or 3% if wilting is not possible, he said.

Older swards with less ryegrass are reportedly showing lower sugars. Current conditions are favourable for increased sugars, Dr. Patton added.

Farmers were also reminded that local Teagasc offices will test grass sugars and nitrates to establish best options for cutting.

Grass nitrates and wilting

It was also outlined that grass nitrates can affect preservation by increasing buffering capacity.

However, there is good evidence that sugar levels are actually the more important consideration, the Teagasc dairy specialist said.

“A grass crop will – on average – use up two units of nitrogen (N) per day for first cut, and more during good growing conditions.

Nonetheless, this is only a general rule and should not unduly delay cutting date. Local Teagasc offices will test for nitrates in addition to sward sugars

Continuing, Dr. Patton explained that wilting is very beneficial to silage preservation where sugars are marginal and/or nitrates remain elevated.

“The aim should be to increase crop DM to 27-30%. This is best achieved by tedding out rows and wilting for 24 hours in good conditions. Data from Teagasc Grange shows that grass left in larger rows (3m plus) will not dry sufficiently to be effective.

“Where surplus bales are made from shorter leafy grass, wilting to 30% plus will result in better preservation and bales that hold their shape over longer storage periods. There will also be a reduction in baling costs,” he concluded.