1. Agricultural Catchments Programme Teagasc, Environ. Research Centre; Johnstown Castle Co Wexford Ireland
2. Institute for Global Food Security School of Biological Sciences Queen's Univ.; Belfast BT9 5AG Northern Ireland UK
3. Agri-Food and Biosciences Institute; Newforge Lane Belfast BT9 5PX Northern Ireland UK
4. Teagasc; Environment Soils and Land Use Dep.; Johnstown Castle Co. Wexford Ireland