Towards a National Soils Database in the Republic of Ireland.
Deirdre Fay and David McGrath. Teagasc, Environment Research Centre, Johnstown Castle, Wexford, Ireland
During 1995 and 1996 soils representing 22% of the land area of Ireland were systematically sampled in the South-Eastern region of the country. Samples of soil from all land use categories (grassland, tillage, forest and peatland) were analysed for a range of heavy metals. Soil samples were archived and are available for future analyses as required. Soil parameters investigated included pH, and organic matter, as well as, major components, aluminium, iron, and manganese and trace elements (heavy metals), arsenic, cadmium, chromium, cobalt, copper, lead (Pb), mercury, nickel, selenium (Se) and zinc. Results were statistically analysed and frequency distributions calculated. Geographic distributions were plotted and localized concentrations were found for most elements. Geochemical factors were considered to be largely responsible for most of these localized concentrations. Aerial deposition of Pb and Se was also indicated. Overall, little serious contamination of soils, especially that caused by man, by toxic elements was evident. However, as many as 21% of soils, breached the provisions of the EU Sewage Sludge Directive, for heavy metals in soils. On the basis of this finding it was considered imperative that similar information be obtained for the rest of the country. Consequently this study is currently being extended to include the remaining three quarters of the country. Approximately 1000 soil samples have been collected from predetermined defined positions on the national grid (7.07 km spacing) and will be analysed for a range of chemical and biological parameters. The analytical results generated will be incorporated into the existing database and will be subjected to statistical and geostatistical analysis to evaluate the quality of Irish soil. A baseline database and maps of soil chemical properties will be developed which will form the foundation for a national soil database. A national soil archive and catalogue will be established and maintained. It is envisaged that this study will provide baseline information, which will be incorporated into a proposed national soil information system.