Deirdre Hennessy, Teagasc is leading the Dairy I3S in Ireland. The I3S will have the Demonstration Farm, 10 Lead Commercial Farms, and about 100 outreach farms. Dairy production in Ireland is predominantly spring calving and grass based with cows grazing from February to November. Approximately 96% of the dairy cows fresh intake and 82% on a DM basis is forage based, either grazed grass or grass silage. The average stocking rate on dairy farms is ~2.1 livestock units/ha. Grass based systems in Ireland have been traditionally based on perennial ryegrass swards receiving N fertiliser, recently, our grazing systems are transitioning to grass-white clover systems with reduced N fertiliser input. Our demonstration farm is Teagasc Curtins Research Farm. The research programme on the farm has three farmlets examining three pasture-based systems – grass-only with 225 kg N/ha applied, grass-white clover with 150 kg N/ha and Multispecies Swards with 125 kg N/ha. The research farm is or will be implementing a range of measures to transition towards climate neutrality, e.g. low emissions slurry spreading, using protected urea, planting trees and hedge rows, improving/maintaining high soil fertility, covering slurry storage, etc. A range of data is being collected including soil OM content, soil P, K and pH, annual herbage production, herbage quality, purchased feed, concentrate fed, animal health measurements, milk yield and milk solids yield. ClieNFarm will link closely with the Teagasc SignPost Farm Programme in selecting Lead Commercial farms and Outreach Farms.