Farmers were investigated for more than 400 suspected illegal fires last year and docked support payments in 80 cases.
But with more than 2,000 fires destroying many thousands of acres annually and fewer than one criminal prosecution a year, wildlife groups say the deterrents are not working.
Some farmers use burning to clear gorse and other unwanted vegetation in the run-up to the grazing season.
It is illegal between March 1 and August 31 - vital for nesting birds, breeding wildlife and flowering plants - when even what is intended to be controlled burning can quickly get out of hand.
Already in the six weeks since this year's ban came into effect, there have been dozens of serious fires across the country with counties Wicklow, Cork, Kerry, Donegal and Louth particularly badly affected.
In Kerry, large areas of hillside in Killarney National Park and the Slieve Mish special area of conservation on the Dingle Peninsula have been destroyed.
It is not known for sure whether the fires were started for agricultural purposes or through the actions of other countryside users.
But it is a recurring problem for the park and many other wild and protected areas with firefighters attending to around 2,200 bog, grassland and forest fires every year.
Minister Josepha Madigan, who has responsibility for the National Parks and Wildlife Service (NPWS), has issued stern warnings against any activities that would intentionally, accidentally or negligently cause fire.
She said last week the "full rigour of the law" would be used against those responsible. However, the statistics tell another story as her department admitted just 10 criminal prosecutions were taken in the last 12 years.
Agriculture Minister Michael Creed also warned that farmers found to have burned land during the closed season would be denied money due under the Basic Payment Scheme (BPS).
His department said: "In 2019, 409 cases of possible illegal burning were examined by the department using satellite imagery and other information.
"As a result, payments were withheld in 80 cases. The department is continuing its examination of 2019 cases and is also examining reports of recent fires."
Farmers can receive up to €700 per hectare under the BPS depending on productivity, although the average is around €260.
Pádraic Fogarty of the Irish Wildlife Trust said that anecdotally the BPS sanctions, introduced in 2017, were having some impact but he said more action was needed.
"It's nearly impossible to get a prosecution. You nearly have to catch somebody actually setting fire to the place," he said.
"Docking payments is a start but we need to be more proactive about conservation and engage more with landowners.
"We need to help them figure out new ways of managing the land whether it's re-wilding or high nature value farming. Until that happens I can't see the problem going away."
Dr Andrew Jackson, an expert in environmental law at University College Dublin, said wildlife crime was not taken seriously enough.
"If anything, the closed period in the Wildlife Act is too short since hen harriers for example may have unfledged chicks in their nests on the ground until late September."
He said while prosecution data was sparse, it appeared there had been just one prosecution for wildfires since 2012 and while another was pending, it related mainly to damage to residential property.
"What about the hundreds of other fires every year during the closed period, decimating wildlife and endangering lives?" he said.
"The fact this is still happening, even with our emergency services so stretched, has really caused particular outrage this year."