Protracted negotiations took place with the Government over six months before the package, estimated to be worth around €260 million a year, to the farming sector was accepted.
The ICMSA and Macra na Feirme have also signalled their acceptance of the document, while ICOS, the umbrella body for the co-ops, will meet shortly on the matter.
Last night, Taoiseach Bertie Ahern and the Agriculture and Food Minister Joe Walsh welcomed the decisions of the farming organisations to continue their participation in social partnership.
Mr Ahern said the current round of negotiations had been understandably challenging, given the general economic background. But overcoming challenges through consensus has been a fundamental aspect of the process.
While the agriculture chapter is quite comprehensive and naturally the area of most direct interest to farmers, the Taoiseach said the general overall measures contained in Sustaining Progress are just as important to farmers as to all other sectors of the economy.
Mr Ahern said he is confident ICOS will also sign up to the new agreement very shortly, enabling the entire farming pillar to participate fully in the implementation mechanisms currently being put in place.
IFA president John Dillon said all farmers are seriously concerned over their low-income situation, low prices in milk, beef, grain, and pigs and the major challenges in the CAP reform and WTO negotiations.
Macra na Feirme president Seamus Phelan said elements of the deal did not go far enough in adequately recognising farmers' concerns, but their interests are better served inside the process.
ICSA president John Deegan described the deal as too little too late and said he doubted whether it was right for farm organisations to sign up at this point, particularly when there is such anger among farmers on incomes.