Colin Grennan
Project Title: CLOVERBlueprint: Development of a blueprint for the establishment of white clover into existing grass swards in pasture-based production systems (VISTAMILK)
Biography: Colin is investigating the establishment blueprint of white clover in pre-existing perennial ryegrass swards through over-sowing. His research focuses on how white clover can be successfully introduced into existing perennial ryegrass swards through over-sowing, with particular attention to factors such as establishment methodology, sowing depth, seeding rate, sowing date & post sowing grazing management in suitable fertile paddocks with little or no clover content.
White clover can reduce chemical nitrogen requirements by fixing atmospheric nitrogen through rhizobium bacteria in its root nodules, while also providing highly digestible & higher crude protein content. Successful establishment and persistence can therefore maintain pasture and animal performance with lower fertiliser inputs, reducing costs and the environmental impact associated with nitrogen usage.
Colin studied BSc in Land Management in Agriculture at SETU Waterford graduating with a first-class honours in 2026 and has a strong interest in white clover and grassland management. He comes from a pedigree-registered Holstein Friesian herd in County Laois and also gained practical grass based experience in New Zealand. This background has given him a practical understanding of pasture-based dairy systems and the challenges farmers face when trying to improve productivity while reducing inputs.
Teagasc email colin.grennan@teagasc.ie
University email colin.grennan@ucdconnect.ie
Teagasc Research Programme Animal and Grassland Research and Innovation Programme
Research Location Teagasc Moorepark – Animal and Grassland Research and Innovation Centre
University University College Dublin
Teagasc Supervisor Dr. Michael Egan & Dr. Sarah Walsh
University Supervisor Prof. Kevin McDonnell
Funder VISTAMILK