Dr. Deirdre Hennessy (Teagasc; AGRI; female; FWCI – 1.41) is a lecturer in sustainable agriculture at University College Cork. Deirdre is a grassland researcher focusing on white clover, nitrogen use efficiency, grass growth, and pasture image analyses. She has published >95 peer-reviewed papers and has more than 1,600 citations. Deirdre is/was involved in externally funded research projects (finished or in progress) worth in excess of €66M. She is/was Work Package (WP) leader on FP7 and H2020 projects and principal investigator on competitive Irish projects. Examples of impact include:

• Led the research programme which showed that using white clover in grazed swards can reduce nitrogen fertiliser application in grazing systems by 100 kg N/ha. This led to the Department of Agriculture, Food and the Marine introducing the condition that farmers in derogation must include white clover in all new reseeds.
• Principal Investigator of the DAFM-funded Research Stimulus Fund project ‘Modelling for Increased Grazing Management Precision on Irish Grassland Farms’. A key outcome of that project was the development of the MoSt grass growth model, which is used by Teagasc to provide weekly grass growth predictions for farms across Ireland. These predictions are widely published, including in the Grass10 newsletter, the Irish Farmers Journal, and the Met Éireann Farming Forecast on RTÉ 1 every Sunday.
• Led the multidisciplinary ‘Grass to Milk’ research project at Teagasc, which developed key indicators for grass-fed milk. This research is used by Ornua in marketing Irish pasture-fed milk and milk products.
• Collected the grassland images and associated measurement data in the Irish Grass Clover Dataset (VistaMilk), which has been made available through Zenodo.