Soils of County Offaly Began in the Early 1970'S and the Fieldwork Was Completed in the Late 1980'S
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Soil Survey Bulletin No. 43 ISBN 1 84170 409 1 SOILS of Co. OFFALY by R.F. Hammond and L.E. Brennan National Soil Survey of Ireland AGRICULTURE AND FOOD DEVELOPMENT AUTHOHITY "The quality of this soil is more generally, either a deep moor or a shallow gravelly loam, the moist season being most favourable to the produce it yields and the moors very productive in dry summers" Charles Coote, 1801 Published by Teagasc, 19, Sandymount Avenue, Dublin 4. Ireland © Teagasc, 2003 Origination by Keystrokes, Dublin Printed by Grehan Printers, Dublin ii PREFACE The survey of the soils of County Offaly began in the early 1970's and the fieldwork was completed in the late 1980's. The contribution of Dr. Pierce Ryan, then Head of the National Soil Survey of Ireland, who was instrumental in setting up the Survey is acknowledged. The reorganisation of An Foras Taliintais in 1987/88 and subsequent interregnum through re- deployment of staff to other duties effectively put soils report writing on hold for several years. However, with perseverance this publication, Soil Survey Bulletin No. 43, presents the findings of the Soil Survey of County Offaly, which is the twelfth county soil survey bulletin to be published. Dr. Robert Hammond and Mr. L.E. Brennan were responsible for the field mapping which commenced in 1971. This type of survey is a joint effort between many interested parties. The contributions of Mr. Sean Diamond and Mr R Parle are acknowledged in the correlation and editing of the soils descriptions and the section on trace elements, respectively. Mr. T. Gleeson helped in the preparation and Mr. L.E. Brennan carried out the analyses in the section on soil physical characteristics and pollution susceptibility (Chapters 8 and 9). The late Mr. T.F. Finch carried out the stone counts for the different classes of soil parent materials and the late Dr. T Gately co-operated in the preparation of data for the malting barley survey in the 1970's. Dr. M.J. Conry was associated with the survey of the Hill and Mountain soils. Mr. Michael Bulfin contributed information on aspects of land use in relation to forestry. The bulletin was compiled and word-processed in the main by Dr. R.F. Hammond. Dr. M.J. Conry (Teagasc) and Dr. J.F. Collins (NUI, Dublin) assisted in technical editing and overall editing was by Dr. Con O'Rourke. Acknowledgements are given to the secretarial members, Sharon McAuley, Jackie Smith and James Oberlander, of the Veterinary Epidemiology and Tuberculosis Investigation Unit, Faculty of Veterinary Medicine, NUI Dublin who carried out word processing in the intervening years. Dr. R.F. Hammond, Dr. J.F. Collins and Dr. C. O'Rourke took the photographs that illustrate the bulletin. Mr. J. Lynch and Mr. V. Staples prepared the Soil and Land Use Capability maps. The Quaternary Map prepared by Dr. W. Warren and Dr. R.F. Hammond was a joint cartographic effort between the Geological Survey of Ireland (Sarah-Jane Burns and Robbie Meehan) and the Geographical Information Technology section of the Veterinary Epidemiology and Tuberculosis Investigation Unit, NUI Dublin (Guy McGrath). Funding of this map by the Geological Survey of Ireland is also gratefully acknowledged. The laboratory staff of the Soil Survey Laboratory, the Soil Fertility and Soil Chemistry Department and Plant Nutrition and Biochemistry Department, Johnstown Castle, provided the analytical data. Acknowledgements are due to the Teagasc Advisory Staff, especially Michael Hassett (Chief Agricultural Officer (CAO), Co. Offaly) now retired and his staff during the field work and Mr. T. Collins, CAO, for his contribution to the chapter on Farming in County Offaly. The climatic data were provided by Met Eireann (The Meteorological Service). iii Soils Co. Offaly The colour maps were printed by the Ordnance Survey, which was also the source of the base maps for the field mapping. The printed maps are based on the Ordnance Survey by permission of the Government. Grateful acknowledgement is made to all those contributors mentioned here and to others who helped in various ways. Dr. John Lee, Head, Environmental Research Centre, Teagasc, Johnstown Castle, Wexford. 2002 IV CONTENTS PREFACE ...................................................................................................................................................iii CHAPTER 1 GENERAL DESCRIPTION OF THE AREA Location and Extent....................................................................................................................................1 Topographic Features ................................................................................................................................I Catchment Basins ........................................................................................................................................5 Climate ........................................................................................................................................................5 Precipitation.......................................................................................................................................5 Temperature .......................................................................................................................................9 Sunshine ..........................................................................................................................................10 Crop growing season .......................................................................................................................10 Soil moisture deficits.........................................................................................................................12 CHAPTER 2 BEDROCK AND PLEISTOCENE GEOLOGY OF CO. OFFALY Bedrock.......................................................................................................................................................15 Introduction ..............................................................................................................................................15 Silurian rocks ..:i...............................................................................................................................15 Devonian rocks.................................................................................................................................15 Carboniferous sediments .................................................................................................................16 Carboniferous volcanics...................................................................................................................17 Pleistocene Geology ...................................................................................................................................17 Morphology ......................................................................................................................................17 Petrography of the deposits............................................................................................................. 18 Stratigraphy .................................................................................................................................... 19 Pattern of glaciation and deglaciation .............................................................................................19 The eskers........................................................................................................................................ 20 CHAPTER 3 CONSIDERATIONS IN SOIL SURVEY Introduction .............................................................................................................................................. 23 The soil profile........................................................................................................................................... 23 Soil horizons .................................................................................................................................... 23 Factors of soil formation .......................................................................................................................... 26 1) Parent material............................................................................................................................ 26 2) Climate ........................................................................................................................................ 26 3) Living organisms ........................................................................................................................ 26 4) Topography.................................................................................................................................. 27 5) Time ............................................................................................................................................ 27 v Soils Co. Offaly Differences and similarities among soils................................................................................................. 28 Soil Series........................................................................................................................................ 28 Soil variants .................................................................................................................................... 28 Other soil units ................................................................................................................................ 28