With an ever-increasing demand for more food supply, agricultural scientists will have to search for new ways and technologies to promote food production. In recent decades, plant growth regulators (PGRs) have made great strides in promoting plant growth and development. PGRs are organic compounds which have the ability to dramatically affect physiological plant processes when present in extremely low concentrations (in the range of micro-to picograms). Although all higher plants have the ability to synthesize PGRs endogenously, they do respond to the exogenous sources most likely due to not having the capacity to synthesize sufficient endogenous phytohormones for optimal growth and development under given climatic and environmental conditions. In recent years, PGRs have established their position as a new generation of agrochemicals after pesticides, insecticides and herbicides. Interest in the commercial use of PGRs for improving plant growth and crop yields is also increasing because of their non-polluting nature. The use of PGRs in the post-harvest technology is well established and many new breakthroughs have recently been revealed.

Salinization of soils is a major threat to irrigated agriculture and counteracts the targets of costly public infrastructure investments. In this study, salinization is regarded as the outcome of an institutional arrangement which impedes the effective implementation of well-known and well-established control measures be they technical, managerial or economic. In public irrigation systems neither the management units nor the farmers are offered any incentives towards the control of high groundwater levels and salinization if the management units are embedded in a highly centralized non-market institutional setting. The author answers the question under which conditions management units and irrigators are active in halting and reversing the process of salinization.

Reservoirs generally consist of sandstones or carbonates exhibiting heterogeneities caused by a wide range of factors. Some of these formed depositionally (e.g. as channels, palaeosols, clay seams or salts), others may be diagenetic in origin (e.g. carbonate or silica cemented zones, authigenic clays, karstic surfaces). The severity with which diagenesis affects rock systems results from the interplay between the diagenetic process itself and the timescale over which it operated. The book provides a wide-ranging overview of diagenetic processes and responses in calcareous, argillaceous, arenaceous and carbon-rich (microbial and organic) sedimentary systems. It introduces diagenetic concepts, reviews existing knowledge, and shows how existing qualitative approaches might be developed in more quantitative ways. Several chapters consider mass balance calculations and the temporal and spatial aspects of diagenetic processes. It is unique, as a textbook, in providing such a breadth of diagenetic subject range and such depth of coverage in each topic. It provides a source reference for advanced students and professionals active in reservoir and aquifer studies.

Diazotrophic bacteria convert atmospheric nitrogen to plant-useable form and this input of nitrogen through biological fixation is of great agronomic importance. The contributions presented in this volume relate to free-living nitrogen fixers and the diazotrophs associated with plants. Symbiotic association of Frankia with non-legumes and cyanobacterial associations are also discussed. Research topics covered in this volume include the biochemistry and genetics of diazotrophs, recent developments in improvement of plant-microbe interactions and their molecular basis, the use of molecular probes in taxonomy and ecology of diazotrophs and reports on field applications, agronomic importance and improvement in methodologies for assessing their contribution to plants. This book provides valuable information not only for researchers working in the field of biological nitrogen fixation but also for biochemistry, molecular biologists, microbiologists and agronomists.

Modeling and simulation were introduced to the earth sciences about four decades ago. Modeling has proven its worth and now it is an accepted procedure for analyzing and solving geological problems. The papers in this collection are focused on modeling sediment deposition and sedimentary sequences and have a decidedly practical flavor. Some of the leading simulation packages, such as CORRELATOR, SEDFLUX, SEDpak, SEDSIM, STRATA, and STRATSIM are applied to problems in hydrocarbon exploration, oil production, groundwater development, coal-bed appraisal, geothermics, and environmental diagnosis. All of these subjects fall under the broad heading of sedimentary basin analysis. The fifteen papers in this volume are written by internationally recognized experts from academia and industry. The contributions represent the status of geologic modeling and simulation at the start of the 21st century, and will give the reader an insight into current research problems and their possible solutions.

The frrst attempts to use physical methods in agriculture can be found in nineteenth century as a necessary component of farm and food machinery. There were mechanics, electricity and physical chemistry that were the first physical disciplines used in agriculture and food industry. In the same time period the studies on physical properties of soils started to be one of main topics of soil science. The twentieth century was a century of research on physical properties of agromaterials. The physical properties of agromaterials have been studied e. g. in the USA, where a big role has been played by ASAE (1907), and in the Soviet Union where the special Institute of Agrophysics was founded (1932) by Academician Ioffe. The ASAE's activity was enlarged in 1960s and 1970s, especially with the role playing by the Mohsenin's group and its followers. At that time the Institute of Agrophysics of Polish Academy of Sciences was founded in Lublin and conferences on physical methods in agriculture began to be organised. The participants of the last conference - "Physical Methods in Agriculture - Approach to Precision and Quality," held on August 27-30, 2001, have prepared the basis for this book. Part of the conference participants decided to enlarge their conference papers to be more general and more instructive in relation to further development of the science. New papers prepared under this deciSion were reviewed, discussed and revised, repeatedly, to be presented in this book.

Collapsing engineering soils are a formidable hazard around the world. These difficult materials also include some of the world's most fertile agricultural soils, fostering dense human populations which are therefore increasingly at risk. Despite an impressive literature on the engineering aspects of collapsing soils, these materials are coming under increasing scrutiny by scientists in other fields. This is most evidently the case with soil scientists, stratigraphers and sedimentologists. Past earth surface conditions have a direct influence on the detailed behaviour of collapsible soils: as a complement, these materials also provide detailed data on changing global climates. The selected papers presented here highlight the common ground between three scientific groups with a vested interest in a better understanding of collapsible soils.

Sedimentation and Tectonics in Rift Basins: Red Sea - Gulf of Aden presents new case studies and synthesises the results of recent research on the sedimentological evolution of the Red Sea - Gulf of Aden rift system. This rift basin is generally regarded as the best natural geological laboratory in the world in which to study the processes of rift formation. Uplift of the rift margins in an arid climate results in extensive three-dimensional exposures of pre- and syn-rift strata and associated structures. These serve as analogues for the understanding and hydrocarbon exploration of deeper buried rift-systems on continental margins such as the North Sea and the Atlantic margins. The Red Sea - Gulf of Aden rift is also exceptional in that its stratigraphy spans all stages from pre-rift environments, syn-rift continental to marine environments through the rift to drift transition to post-rift sea-floor spreading. The work is arranged in eight sections: following a review of the sedimentology and stratigraphy of rift basins, the magmatism and structural evolution of the Red Sea - Gulf of Aden rift is reviewed. Subsequently, new case studies are presented of the early rifting environment, syn-rift sedimentation, tectonics and diagenesis, evaporites and salt tectonics. Post-rift sediments of the axial trough are then discussed along with studies of reefs, coastal zone and shelf sediments, and the tectonic geomorphology of the rift margin escarpment. This work results from extensive new research in the rift basin largely carried out under collaborative research projects by European and Middle Eastern geologists. It will be an invaluable reference work for geoscientists in the hydrocarbon, groundwater and mineral extraction industries, as well as for researchers in university departments of earth sciences, mining and physical geography.

Acknowledgements Conference Summary R. D. EVANS, A. PROVINI, J. S. MATIICE, B. T. HART and J. WISNIEWSKI/Interactions Between Sediments and Water: Summary of the 7th International Symposium 1-7 Sediment I Water Dynamics D. E. WALLING and W. HE /Investigating Spatial Patterns of Overbank Sedimentation on River Floodplains 9-20 R. JEPSEN, J. ROBERTS and W. LICK / Effects of Bulk Density on Sediment Erosion Rates 21-31 T. G. MILLIGAN and D. H. LORING / The Effect of Flocculation on the Size Distributions of Bottom Sediment in Coastal Inlets: Implications for Contaminant Transport 33-42 loG. DROPPO, G. G. LEPPARD, D. T. FLANNIGAN and S. N. LlSS / The Freshwater Floc: A Functional Relationship of Water and Organic and Inorganic Floc Constituents Affecting Suspended Sediment Properties 43-53 C. H. TSAI and J. Q. HU / Flocculation of Particles by Fluid Shear in Buffered Suspensions 55-62 P. M. STONE and D. E. WALLING / Particle Size Selectivity Considerations in Suspended Sediment Budget Investigations 63-70 Q. HE and D. E. WALLING / Spatial Variability of the Particle Size Composition of Overbank Floodplain Deposits 71-80 C. YEN and Y. LIN KEY / Variations of Bed Surface Sediment Size in a Channel Bend 81-88 M. STONE and B. G. KRISHNAPPAN / Transport Characteristics of Tile-Drain Sediments From an Agricultural Watershed 89-103 U. KERN and B. WESTRICH / Sediment Budget Analysis for River Reservoirs 105-112 A. I. PACKMAN, N. H. BROOKS and J. J.

Rural areas need to fulfil a large variety of functions and to accommodate many activities. The complexity of the problems, limited funds, and the almost irreversible character of some interventions result in a compelling need to evaluate ex ante the effects of alternative solutions for designation of land, for measures to develop infrastructure, and for soil and water management. Scenario studies are undertaken to help manage the complexity, to place bounds on uncertainties, and to create new visions. After an overview of the nature, variety and scope of scenario studies, the book illuminates various European examples and reviews, under the following headings: regional soil and water management; nature development and landscape quality; rural planning and the future of regions.

The Fifth International Symposium on Nitrogen Fixation with Non-legumes was held in Florence (Italy) on 10-14 September, 1990. Earlier Symposia of this series were held in Piracicaba (Brazil), Banf Alberta (Canada), Helsinki (Finland) and Rio De Janeiro (Brazil). The Symposium's main objectives were to bring together scientists working in many different fields of nitrogen fixation, to stimulate discussion on this important process and to have an appraisal of the most recent studies concerning nitrogen fixation with non-legumes. The Symposium was attended by 230 scientists from 32 different countries. This volume collects the contributions of 65 lectures and 87 posters, which are an up-to-date account of the state of knowledge on biological nitrogen fixation with non-legumes. The book provides a valuable reference source not only for specialists in nitrogen fixation, but also for researchers working on related aspects of agronomy, biochemistry, genetics, microbiology, molecular biology and plant physiology. It is with great pleasure that we aknowledge the contributions of the authors in assuring the prompt pubblication of this volume. We would also like to express our thanks to Kluwer Academic Publishers B.V. for the publication of these Proceedings. M. Polsinelli R. Materassi M. Vincenzini ORGANIZING COMMITTEE President M. Polsinelli M. Vincenzini Secretary F. Favilli Treasurer E. Galli E. Gallori L. Giovannetti R. Materassi M.P. Nuti M.R. Tredici SCIENTIFIC COMMITTEE M. Bazzicalupo Florence, Italy H. Bothe Cologne, West Germany R.H. Burris Madison, U.S.A.

At the dawn of the 21st century, biotechnology is emerging as a key enabling technology for sustainable environmental protection and stewardship. Biotechnology for the Environment: Strategy and Fundamentals captures the dynamism of environmental biotechnology as it addresses the molecular functioning of microorganisms as cleanup agents, their communal interactions in natural and polluted ecosystems, and the foundations of practical bioremediation processes. Chapters on biological pollution control in the chemical industry, biodegradation of persistent molecules (halogenated compounds, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, pesticides, detergents, etc.), microbial diversity with impact on global change, bioaugmentation strategies, and sensors for ecotoxicological monitoring, will be of value to environmental scientists, engineers, and decision-makers involved in the development, evaluation, or implementation of biological treatment systems.

For information on Soil Remediation, see Focus on Biotechnology volume 3B, and for information on Waste Water and Waste Gas Handling, see Focus on Biotechnology volume 3C.

TO THE MODEL EVALUATION 1. MODELLING SOIL EROSION BY WATER l 2 John Boardman and David Favis-Mortlock 1 School of Geography and Environmental Change Unit Mansfield Road University of Oxford Oxford OX1 3TB UK 2 Environmental Change Unit University of Oxford 5 South Parks Road Oxford OX1 3UB UK Introduction This volume is the Proceedings of the NATO Advanced Research Workshop 'Global Change: Modelling Soil Erosion by Water', which was held on II-14th September 1995, at the University of Oxford, UK. The meeting was also one of a series organised by the IGBP 1 GCTE Soil Erosion Network, which is a component of GCTE's Land Degradation Task (3.3.2) (Ingram et aI., 1996; Valentin, this volume). One aim of the GCTE Soil Erosion Network is to evaluate the suitability of existing soil erosion models for predicting the possible impacts of global change upon soil erosion. Due to the wide range of erosion models currently, in use or under development, it was decided to evaluate models in the following sequence Favis-Mortlock et al., 1996): * field-scale water erosion models * catchmenr-scale water erosion models * wind erosion models * models with a landscape-scale and larger focus. As part of this strategy, the first stage of the GCTE validation of field-scale erosion models was carried out at the Oxford NATO-ARW. I A list of Acronyms fonns Appendix A.

John E. Mylroie and Ira D. Sasowsky' Caves occupy incongruous positions in both our culture and our science. The oldest records of modem human culture are the vivid cave paintings from southern France and northern Spain, which are in some cases more than 30,000 years old (Chauvet, et ai, 1996). Yet, to call someone a "caveman" is to declare them primitive and ignorant. Caves, being cryptic and mysterious, occupied important roles in many cultures. For example, Greece, a country with abundant karst, had the oracle at Delphi and Hades the god of death working from caves. People are both drawn to and mortified by caves. Written records ofcave exploration exist from as early as 852 BC (Shaw, 1992). In the decade of the 1920's, which was rich in news events, the second biggest story (as measured by column inches of newsprint) was the entrapment of Floyd Collins in Sand Cave, Kentucky, USA. This was surpassed only by Lindbergh's flight across the Atlantic (Murray and Brucker, 1979).

For a long time microbial ecology has been developed as a distinct field with in Ecology. In spite of the important role of microorganisms in the environ ment, this group of 'invisible' organisms remained unaccessable to other ecologists. Detection and identification of microorganisms remain largely dependent on isolation techniques and characterisation of pure cultures. We now realise that only a minor fraction of the microbial community can be cultivated. As a result of the introduction of molecular methods, microbes can now be detected and identified at the DNA/RNA level in their natural environment. This has opened a new field in ecology: Molecular Microbial Ecology. In the present manual we aim to introduce the microbial ecologist to a selected number of current molecular techniques that are relevant in micro bial ecology. The first edition of the manual contains 33 chapters and an equal number of additional chapters will be added this year. Since the field of molecular ecology is in a continuous progress, we aim to update and extend the Manual regularly and will invite anyone to deposit their new protocols in full detail in the next edition of this Manual.

Nitrogen is the most limiting element for crop production. Traditionally, expensive commercial fertilizers are used to correct soil nitrogen deficiencies. Indeed, 50% of the increase in rice yields after World War II can be attributed to increased fertilizer nitrogen use. Although an increased rate of fertilizer nitrogen application has been advocated to meet the growing demand for food, it is unrealistic to advise the farmers to apply fertilizers they could hardly afford, and whose prices are likely to escalate in the years ahead. In addition, when they are not applied judiciously there are problems of environmental pollution as plants are capable of taking up only a relatively small portion of the applied nitrogen, a substantial amount being lost through various chemical and biological processes. The exploitation of cheaper alternatives or supplements to fertilizers have therefore gained much interest in recent years. Our increased interest in biological nitrogen fixation as a supplement or alternative to nitrogen fertilizers led to the convening of a consultants' meeting on `The Role of Isotopes in Studies on Nitrogen Fixation and Nitrogen Cycling by Blue-Green Algae and the Azolla-Anabaena azollae Association', in Vienna from 11--15 October 1982. The consultants' group recommended that the Joint FAI/IAEA Division of Nuclear Techniques in Food and Agriculture embark on a coordinated research programme in this field and that initial emphasis should be placed on Azolla-Anabaena symbiosis. As a result, such a programme was initiated in 1984, which was concluded in 1989. The results and conclusions reported here are those that were generated during the five years of its operation.

Geothermics in Basin Analysis focuses on the study of sedimentary basins, stressing essential parts of problems in which geothermics is involved. Subject matter includes the measuring of temperature logs and capturing of industrial temperature data and their interpretation to delineate subsurface conditions and processes, the importance of porosity and pore filling for modeling thermal fields, the thermal insulation of shales, geothermal anomalies associated with mud diapirs and basin hydrodynamic regimes, temperatures related to magmatic underplating and plate tectonics.

Fungi are among the most versatile and diverse groups of organisms in their morphology, life cycles, and ecology. This has provided endless fasci nation and intrigue to those who have studied fungi, but it has also made it difficult to understand fungal biology from the perspective of the broader fields of evolution, ecology, genetics, and population biology. That is changing. Details of fungal biology have been elucidated at an exciting pace, increasingly allowing us to understand fungi on the bases of general biological principles. Moreover, many who study fungi have lately emulated some of the great mycologists and plant pathologists of the early years in applying an insight born of broad perspective. This change has been particularly apparent in fungal population biology. In this book, many of those at the forefront of that change summarize, integrate and comment on recent developments and ideas on populations of fungi. By taking a broad perspective, they show how new information on fungi may contribute to concepts and ideas of biology as a whole. Just as important, they contribute to further invigoration of fungal population research by illuminating mycology with new ideas and concepts, derived in part from other biological fields.

Since 1956 the author has been making extensive and detailed investigations of saline lakes on the Qinghai-Tibet plateau. On the basis of large amounts of reliable first-hand data and multidisciplinary analysis, the book deals with the temporal-spatial evolution of the plateau saline lakes and the prospects for inorganic salts and organic resources and their exploitation and protection, as well as the relationships between saline lakes and global changes. This book is the first English monograph on saline lakes on the Qinghai-Tibet Plateau - the Roof of the World'. Compared with books about saline lakes in other areas of the world, this monograph is written in a multidisciplinary, comprehensive and systematic way. It may be used by graduate students, teachers, researchers, field geologists and engineers as a reference book in research, teaching, etc.

all such systems are important, the Proterozoic column This volume concerns the geology of China, and it examinesthat concern by expositionsofthe stratigraphy, possibly is unique in its continuous sedimentary devel the paleogeography, and the tectonics ofthat remarkable opment and in its reference section of global rank. In paleogeography, this volume describes and illustra country. In this sense, therefore, our aims and purposes are explicit in the title. The senior author and his tes first the broad distribution of Proterozoic deposits. colleagues, furthermore, do not have in mind any special Succeeding descriptions and illustrations trace the ebb and flow of shallow marine waters across China as or specific audience. This volume is quite simply for all geologists. By far the majority will be those whose Phanerozoic time of more than 600 million years elapses native tongue is English, or those who understand from the beginning of the Cambrian to the present. In structure, this volume emphasizes the importance English. Not to be overlooked, moreover, is the large number ofChinese geologists who not only read English of paraplatforms, platforms, geosynclines, and great but also who themselves write studies in English that east-west zones of fracture in the Precambian, also the appear in publications in both their homeland and effects of these early structural elements on structure abroad. in the ensuing Phanerozoic. In the Phanerozoic itself, north-south stress developed in the pre-Phanerozoic A constantly growing interest in the geology of China continued through much of the Paleozoic."

From the Preface: The chapters of this book contain contributions from an international group of specialists. They address some important themes in both modern and ancient reef systems. Some chapters contain 'snapshots' of reefs of particular intervals, while others touch on relevant themes of both modern and ancient reefs - themes that weave their way through reefs of all ages. This book opens and sets the stage with an introduction to both modern and ancient reefs and reef ecosystems. This chapter is also intended as a basic introduction for students, general geologists, and professionals or others who may be unfamiliar with reefs and reef ecosystems. The chapter addresses the living coral reef ecosystem, stressing among other relevant factors, the importance of ecological and physical interactions between the organisms and their environment. The chapter also addresses mass extinction and provides a general overview of the history of reefs.

James O. Leckie Environmental Engineering and Science Program, Department of Civil and Environmental Engineering, Stanford University, Stanford, California 94305-4020, USA Nearly 10 years have passed since the beginning of the systematic studies of the Lerma-Chapala Basin coordinated by the Instituto Mexicano de Tecnologia del Agua. Although many public and private institutions, universities and research centers have conducted studies on the Lerma Chapala Basin over the last two decades, the need for a comprehensive summary of the findings of those studies has become increasingly obvious and important for this critical water resource. The Lerma-Chapala Basin is located in the central part of Mexico, and partly occupies five states. The watershed comprises the Lerma river and Lake Chapala. With a length of over 700 km, the tributary watershed covers 2 approximately 54,000 km . The basin accounts for more than one-third of the country's economic activity, one-fifth of all commerce and one-eighth of the nation's agricultural land. The watershed receives 3% of the country's total rainfall, less than 1 % of the runoff, and accounts for 13% of the total groundwater.

A knowledge of clay is important in many spheres of scientific endeav our, particularly in natural sciences such as geology, mineralogy and soil science, but also in more applied areas like environmental and mater ials science. Over the last two decades research into clay mineralogy has been strongly influenced by the development and application of a num ber of spectroscopic techniques which are now able to yield information about clay materials at a level of detail that previously would have seemed inconceivable. This information relates not only to the precise characterization of the individual clay components themselves, but also to the ways in which these components interact with a whole range of absorbate molecules. At present, however, the fruits of this research are to be found principally in a somewhat widely dispersed form in the scientific journals, and it was thus considered to be an appropriate time to bring together a compilation of these spectroscopic techniques in a way which would make them more accessible to the non-specialist. This is the primary aim of this book. The authors of the various chapters first describe the principles and instrumentation of the individual spectro scopic techniques, assuming a minimum of prior knowledge, and then go on to show how these methods have been usefully applied to clay mineralogy in its broadest context."

The first edition of Practical Sedimentology contained dis ACKNOWLEDGMENTS cussions of principles and techniques that could be applied to the analysis of sediments in the field and in laboratories sup Colleagues at the University of Canterbury and the Univer plied with inexpensive and commonly available equipment. sity of New England, Lismore, have helped with practical When considering a revised edition, we felt that it was inap advice on their experiences with various methodologies dis propriate to restrict consideration to the simple and common cussed in this volume. At the University of Canterbury, we techniques because so many modern analyses of sediments are particularly grateful to K. Swanson for advice on prepar use sophisticated and often expensive equipment to examine ing materials for scanning electron microscopy and paleonto sediments and sedimentary rocks. A review of the wide range logical specimens; to G. Coates (working at the university at of available techniques and equipment was not feasible in the the time of the first edition of Practical Sedimentology) for same volume as a review of principles. The original intent to compilation of, and additions to, the procedures for textural analysis and some tables and sketches; to Ted Montague for produce a concise summary of practical sediment studies in an inexpensive format was maintained, but now in the form the bulk of the chapter on borehole sedimentology; to Dr. J.

In the Netherlands the Institute for Soil Fertility Research plays a major role in soil biological, soil physical and plant nutritional research on the availability of nitrogen to crops. Main subjects of research are nitrogen turnover in the crop-soil ecosystem through biological transformations, nitrogen transport through the soil and nitrogen losses by leaching, denitrification and volatilization, and nitrogen use efficiency of various crops and cropping systems. The current knowledge in the different fields of research is integrated in simulation models. Simulation models not only make it possible to summarize and structure knowledge, but also, after verification, to extra- late the knowledge to situations different from the situations that have actually been studied. Such research is also carried out in other European and non-European countries. To compare the various simulation models currently in use, a workshop was organized by the Institute for Soil Fertility Research on 5-6 June 1990 on the occasion of its centennial. The title of the workshop was 'Nitrogen turnover in the soil-crop:: cosystem: modelling of biological transformations, transport of nitrogen and nitrogen use efficiency'. The 40 Jarticipants, who came from Canada and various European countries, were requested to run their model with data Jrovided by the Institute prior to the workshop. Data from 18 cases were made available to the participants: three ocations, three treatments, and two seasons.