SOILS AND SOIL CONDITIONS IN SEDIMENTS OF THE RAMADI PROVINCE (IRAQ), THEIR GENESIS, SALINITY, IMPROVEMENT AND USE-POTENTIAL. Dr. H. M. YAHIA PUBLICATIES VAN HET FYSISCH-GEOGRA- FISCH EN BODEMKUNDIG LABORATORIUM VAN DE UNIVERSITEIT VAN AMSTERDAM nr. 18 (1971) Scanned from original by ISRIC - World Soil Information, as ICSU World Data Centre for Soils. The purpose is to make a safe depository for endangered documents and to make the accrued information available for consultation, following Fair Use Guidelines. Every effort is taken to respect Copyright of the materials within the archives where the identification of the Copyright holder is clear and, where feasible, to contact the originators. For questions please contact [email protected] indicating the item reference number concerned. SOILS AND SOIL CONDITIONS IN SEDIMENTS OF THE RAMADI PROVINCE (IRAQ), THEIR GENESIS, SALINITY, IMPROVEMENT AND USE-POTENTIAL. Dr. H. M. YAHIA PUBLICATIES VAN HET FYSISCH-GEOGRA- FISCH EN BODEMKUNDIG LABORATORIUM VAN DE UNIVERSITEIT VAN AMSTERDAM nr. 18 (1971) 26^ CONTENTS PREFACE AND ACKNOWLEDGEMENTS CHAPTER 1. CLIMATE AND PHYSIOGRAPHY 1. Climate of Iraq 2. Climate of Ramadi Province a. Precipitation b. Temperature c. Humidity d. Evaporation 3. Vegetation 4. Geology a. Introduction b. Historical geology c. Stratigraphy of the Ramadi Province 5. Physiographic regions a. General b. The Euphrates River Floodplains c. The Euphrates River Terraces d. The Western Desert 6. Sedimentology a. General physiographic differentiation b. Dune formation in the Ramadi area 7. Hydrology a. The regime of the Euphrates River b. Groundwater and seepage in the Ramadi Province c. Flood control d. Soil drainage CHAPTER 2. SOILS OF THE RAMADI AND WESTERN DESERT AREAS 1. Mapping methods a. Field mapping methods b. Aerial photo-interpretation 2. Soil classification 3. Description of the soil map units of the Ramadi area a. The River Levee Soils b. The Low Silted River Levee Soils c. The Low Silted River Basin Soils d. The River Crevasse Soils e. The Point Bar Soils f. The River Bed Soils g. The Desert Colluvium Soils h. The Fan Soils i. The Gypsiferous Desert Soils j. The Meander Belt Soils k. The Fore Land Soils Description of the soil map units in the Western Desert Area a. Introduction b. Soils of the plateau and of the undulating area (stony desert) c. Soils of the rolling and hilly area (mixed gypsiferous desert) d. Soils of the older river terraces e. Soils of the younger river terraces f. Tentative classification of the soils of the Western Desert rnADTPD o MORPHOLOGY AND MICROMORPHOLOGY OF SOME PROFILES IN THE RAMADI PROVINCE AND SOME RELATED PROFILES 59 A. Ramadi Area 1. River Levee Soil a. Morphology b. Micromorphology 2. Silted Low River Levee Soil a. Morphology b. Micromorphology 4. Desert Colluvium a. Morphology b. Micromorphology 5. Bioporosity B. Ttiv/ari^ Area 1. Basin-depression Soil under artificial drainage a. Morphology b. Micromorphology 2. Basin-depression Soil without artificial drainage a. Morphology b. Micromorphology C. Western Desert Area 1. Soil of the plateau and of the undulating area (stony desert) a. Morphology 2. Soil of the rolling and hilly area (mixed gypsiferous desert) a. Morphology D. Results on micromorphology from previous investigations 1. Introduction 2. Ramadi area a. River Levee b. River Basin 3. Haditha area a. Younger Alluvial Terrace 4. Al Qaim area a. Younger Alluvial Terrace 5. Discussion E. Discussions and conclusions on the morphology and micromor­ phology of the soils studied. CHAPTER 4. MINERALOGY OF SOME PROFILES 1. Introduction 2. Mineralogical investigations of the sand fractions a. On the treatment of the sample material b. Heavy mineral distribution shown by three recent sample materials c. The investigated profiles c. 1. Euphrates Floodplain c. 2. Euphrates Terraces Profiles c. 3. Western Desert Profiles c.4. Discussion d. Some laboratory experiments on mineral species occurring in the profiles 3. Mineralogical investigation of the silt and clay fractions a. Result of the X-ray and differential thermal analyses CHAPTER 5. SALINITY AND RELATED PHENOMENA 1. Introduction 2. Definitions and general classification of saline soils 3. The most common ions in the soils and the types of salinity 4. Origin and distribution of salinity in the Ramadi area 5. Groundwater salinity 6. Sabakh and Shura soils in the Ramadi area 7. Horizons related to salinity conditions a. Gypsic horizon b. Salic horizon 8. The influence of salts on crop plants and on natural vegetations 9. Reclamation of the saline and salin-alkali soils CHAPTER 6. LAND CLASSIFICATION 1. Introduction 2. Present Land use and crop experiments a. Present land use b. Crop experiments 3. Soil qualities a. Topography b. Soil texture and structure c. Drainage d. Salinity e. Groundwater salinity 4. Present land use capability a. Assumptions b. Classification system c. Present land use capability map 5. Potential land use capability a. Assumptions b. Potential land use capability map 6. Land management and planning for better land use in the Ramadi area. APPENDICES 184 Appendix 1. Profile and micromorphological descriptions 1.1. Description of soil profiles 1. 2. Description of micromorphology 1. 3. Thin sections Appendix 2. Chemical and physical analyses 2.1. Electrical conductivity 2.2. pH value 2. 3. Soluble cations and anions in 1:1 soil to water extract 2.4. Cation exchange capacity 2.4.1. Of soil materials 2.4.2. Of clay fraction 2. 5. Exchangeable cations 2.6. Gypsum 2. 7. Alkaline-earth carbonates (lime) 2.8. Free iron oxide 2.9. Organic carbon 2.10. K2O of clay fraction 2.11. Particle-size distribution 2.12. Porosity Appendix 3. Mineralogical methods used 3.1. Separation of sand fractions and mount preparation 3. 2. Description of the heavy and light minerals 3. 3. Chemical treatment of silt and clay fractions and their fractionations for X-ray diffraction 3.4. X-ray analyses 3.4.1. Guinier-de Wolff camera 3.4.1.1. Qualitative identification 3.4.1. 2. Semi-quantitative determination (Guinier-de W. c) 3.4.2. Diffractometer analysis 3.5. Differential Thermal Analysis (D. T.A.) Appendix 4. Maps 4.1. Drainage basins of the Mesopotamian Rivers 4.2. Soil maps of the Ramadi and the Western Desert areas 4. 3. Groundwater salinity and soil salinity in the Ramadi Area. 4.4. Soil quality maps of the Ramadi area 4. 5. Land capability maps of the Ramadi area SUMMARY 217 NEDERLANDSE SAMENVATTING 219 BIBLIOGRAPHY 221 PREFACE AND ACKNOWLEDGEMENTS In Iraq, especially after the last two decades, a growing need is felt for information about soil conditions for a sound appraisal of the overall suitability of the land for sustained irrigation farming. Agriculture is the main source of income of the inhabitants of the Ramadi Province, therefore, the study of the soils and their con­ ditions in relation to present and potential land use capability is the main object of our investigations. The contents of this publication deal with climate and physio­ graphy, description and classification of the soils studied, their mor­ phology and micromorphology, mineralogy, salinity, and land classi­ fication. It is hoped that these investigations will contribute to the better understanding of the soil conditions and properties in the Ramadi Province in particular and in the Mesopotamian Plain in general. It is impossible to acknowledge adequately in a few words the criticisms, assistance and encouragement rendered by my professors and colleagues who have assisted me in the completion of this study. First of all I am extremely indebted to Dr. Ir. A. P. A. VINK, professor of physical geography and soil science at the University of Amsterdam, who promoted the completion of this thesis in every way. Without his constructive criticism and generous assistance this study would never have been completed. During his visits to my country and inspecting the areas studied, professor VINK has given me the opportunity to realize all the investigations in optimal conditions; I will never forget it. My profound thanks are due to Dr. H.J. MÜLLER for his advice and valuable comments on the granular and chemical analyses and for his supervision of these analyses which were mainly done by the ana­ lysts of the Laboratory for Physical Geography and Soil Science before his retirement. I am very much indebted to Dr.Ir. J. VAN SCHUYLENBORGH for teaching me about the conditions of stability of clay minerals. His critical reading of the manuscript is gratefully acknowledged. I thank Prof. Dr. R. TA VERNIER and Prof. Dr. C. SYS f or what they have taught me during my study at Ghent University. I am grateful to Dr. Th. W. M. LEVELT for his constructive criticism on clay mineralogy and for the supervision of X-ray analyses. My sincere thanks are due to Drs. P.A. RIEZEBOS. His valuable criticism on sand mineralogy has greatly improved this subject and its presentation. I thank Drs. H.J. MÜCHER for his valuable comments on the micromorphological study and for the supervision of the thin sections. 9 I am much indebted to Drs. J. SEVINK not only for his valuable suggestions and discussions regarding this study but also for his generous help which made possible my accommodation with my family in Amsterdam. I thank Drs. P.C. BEUKENKAMP and Drs. E.A. KUMMER for their help in carrying out the D. T. A. and diffractometer analyses respectively of my samples. Their comments are fully appreciated. I gratefully acknowledge the opportunity I had to discuss several problems with Dr. J. P. DE WAART, Mr. D.F. KAREL, Drs. E.A. KOSTER, Mr. S. KROONENBERG, Drs. F.J.P.M. KWAAD, Mr. C.J. J.H. SCHOTITRN. Drs. R. VAM DER TUIN and Dr. J. WTER3MA. I thank Mr! L. HOITINGA and Mr.