The aim of this Ph.D. was to develop a technology for the remediation of seleniferous soils/sediments and to explore microbial reduction of selenium oxyanions under different respiration conditions and bioreactor configurations. Seleniferous soil collected from the wheat-grown agricultural land in Punjab (India) was characterized and its soil washing was optimized by varying parameters, where addition of oxidizing agents showed a maximum selenium removal efficiency. Aquatic plants, Lemna minor and Egeria densa were used to study phytoremediation of the selenium-rich soil leachate containing oxidizing agents. Additionally, migration of the soluble selenium fraction from the upper to the lower layers and its subsequent reduction and accumulation in the lower layers of the soil column was observed during soil flushing. Furthermore, the soil leachate containing selenium oxyanions obtained from soil washing was treated in a UASB reactor by varying the organic feed. Ex situ bioremediation of selenium oxyanions was studied under variable conditions. An aerobic bacterium (Delftia lacustris) capable of transforming selenate and selenite to elemental selenium was isolated and characterized. Anaerobic bioreduction of selenate coupled to methane oxidation was investigated in serum bottles and a biotrickling filter using marine sediment as inoculum. Finally, the effect of contamination of other chalcogen oxyanions (tellurium) on selenium bioreduction was studied in a continuous system (UASB reactor).

Population growth in the Blue Nile Basin has led to fast land-use changes from forest to agricultural land, which resulted in speeding up the soil erosion processes producing highly negative impacts on the local soil fertility and agricultural productivity. The eroded sediment is transported downstream by water and sinks in the lower basin where it significantly reduces reservoir storage and irrigation canals capacity. The only effective solution to mitigate the sedimentation problem is to limit the sediment inputs from upstream by locally implementing erosion control practices. However, given the vastness and remoteness of the involved areas, this first requires the knowledge of the most critical zones. The book identifies the sources of the sediment depositing in the Lower Blue Nile Basin and quantifies the amounts involved providing essential information for the planning and implementation of any interventions aiming at reducing soil erosion. The methods used consist of extensive field work covering most of the basin, watershed, hydrodynamic and morphodynamic modelling and, for the first time, the mineralogical analysis of the sediment at the sources and sinks. The method is successful in indentifying the areas providing most of the transported sediment, where it is recommended to start with erosion control practices.

Human excreta is a valuable fertilizer for improving soil quality and crop productivity, with a potential to replace or complement the mineral fertilizers. The main challenges related to human excreta regarding agricultural applications are microbial contamination risks, loss of nutrients, and odor issues. Fertilization by lacto-fermented faeces supplemented by biochar has benefits such as improved soil bulk density, nitrate and potassium concentrations as well as the yield and yield components of corn, compared to untreated, simple stored faeces, urine, cattle manure, and unfertilized controls. Even though the mineral fertilizer produced corn with significantly higher height and leaf length, it did not add significantly higher yields than lacto-fermented faeces supplemented by biochar. A faeces treatment process by combined lacto-fermentation with thermophilic composting and biochar supplementation had better reduction of coliforms, Escherichia coli, Enterococcus faecalis and Clostridium perfringens, and higher germination of radish and growth of tomatoes than combined lacto-fermentation with vermicomposting. Urine lacto-fermentation contributed to a pH reduction below 4, a decrease in the ammonium concentration and odor strength, as well as an increase in the germination rates compared to untreated stored urine. The results of this study provide important information that can set the basis for scaling up a sustainable technology for the treatment of source separated human excreta while improving its potential for resource recovery.

This volume presents proceedings from the first Australian-New Zealand Geoenvironment conference. The conference provides a forum for researchers and practitioners in the region to exchange ideas, share information and discuss the effective management of the geoenvironment.

This collection features five peer-reviewed literature reviews on fertiliser use in agriculture. The first chapter examines the role of biofertilizers and consortia of microorganisms to improve the effectiveness of organic fertilization, before moving on to consider the use of animal excrement, including manures, slurry and guano. The second chapter assesses the management of mineral fertilisers and organic manures in relation to its effects on soil health in terms of soil organic carbon and nitrogen, soil acidification and soil microbiology. The third chapter discusses the history, current status, and future needs of fertilizer developments in light of the goal of achieving global sustainability. It reviews developments in using efficient fertilizer sources to meet the needs of advancing yields of modern crop cultivars/hybrids. The fourth chapter reviews some of the approaches used by decision support systems to determine fertiliser application decisions. The chapter highlights direct methods and indirect techniques: simulation models, yield forecasts using data-driven approaches and yield forecasts based on water supply. The final chapter explores the implementation of foliar fertilizer sprays in agriculture for improving crop yield and quality, as well as improving plant performance under abiotic and/or biotic stress threats.

Nitrogen (N) is potentially one of the most complex elements on the Earth. It is necessary for all biological activity, but creates negative impacts on water and air quality. There is a balancing act between deficiency and surplus and the forms of N available further complicate our understanding of the dynamics. Biological fixation provides some plants with N supply while others are totally dependent upon N being available in the soil profile for the roots to extract. Nevertheless, the demand for N will increase because the human population with its increasing growth requires more protein and thus more N. Understanding the global N cycle is imperative to meeting current and future nitrogen demands while decreasing environmental impacts. This book discusses availability, production, and recycling of N in air, water, plants, and soils. It features information on N impacts to soil and water quality, management of N in agroecosystems, and techniques to maximize the use efficiency while minimizing the risks of leakage of reactive N into the environment. This volume in the Advances in Soil Science series is specifically devoted to availability, production, and recycling of N with impact on climate change and water quality, and management of N in agroecosystems in the context of maximizing the use efficiency and minimizing the risks of leakage of reactive N (NO-3, N2O) into the environment.

Indigenous soil and water conservation practices are rarely acknowledged in the design of conventional development projects. Instead, the history of soil and water conservation in Africa has been one of imposing external solutions without regard for local practice. There is a remarkably diverse range of locally developed and adapted technologies for the conservation of water and soil, well suited to their particular site and socio-economic conditions. But such measures have been ignored, and sometimes even overturned, by external solutions. Sustaining the Soil documents farmers' practices, exploring the origins and adaptations carried out by farmers over generations, in response to changing circumstances. Through a comparative analysis of conservation measures - from the humid zones of West Africa to the arid lands of the Sudan, from rock terraces in Morocco to the grass strips of Swaziland - the book explores the various factors that influence adoption and adaptation; farmers' perceptions of conservation needs; and the institutional and policy settings most favorable to more effective land husbandry. For the first time on an Africa-wide scale, this book shows that indigenous techniques work, and are being used successfully to conserve and harvest soil and water. These insights combine to suggest new ways forward for governments and agencies attempting to support sustainable land management in Africa, involving a fusion of traditional and modern approaches, which makes the most of both the new and the old.

The fate of heavy metal particles in the environment is important because they tend to be reactive, mobile, and highly toxic. Reactivity and Transport of Heavy Metals in Soils examines the sometimes complex interactions that occur between metals and the soil they occupy. It discusses basic kinetic concepts and covers the predictability and consequences of metal-soil interactions.
This practical guide presents and explains heavy metal issues crucial to hazardous waste site cleanup, including:

This important text offers a balanced coverage of an area of major human and environmental significance. Lying at the interface of the geosphere, hydrosphere, biosphere and atmosphere, soils are of major importance to an understanding of both natural environmental processes and thoses affected by human activity.
Soils and Environment examines the ways in which soils both influence, and are influenced by, the environment. assuming only a basic scientific knowledge, the book analyses the constituents and properties of soils, and the processes and pathways of soil formation within the context of environmental change. examining soils as components of natural environmental systems, this book offers an understanding of soil-human interactions in landuse systems, environmental problems and landuse management, and soil survey and land evaluation.

Management of Problem Soils in Arid Ecosystems examines the challenges of managing soils in arid and semiarid regions. These soils contain low organic matter, are not leached, and accumulate lime, gypsum, and/or soluble salts, requiring special management and practices. This book discusses how to identify problems, reclaim the soils, and then use them efficiently and economically. Water management and desertification in these areas are also discussed. It contains extensive references as well as 40 tables and illustrations.

This book addresses the importance of soil processes in the global carbon cycle.Agricultural activities considered responsible for an increase in CO2 levels in our atmosphere include: deforestation, biomass burning, tillage and intensive cultivation, and drainage of wetlands.However, agriculture can also be a solution to the problem in which carbon can be removed from the atmosphere and permanently sequestered into the soil. Management of Carbon Sequestration in Soil highlights the importance of world soils as a sink for atmospheric carbon and discusses the impact of tillage, conservation reserve programs (CRP), management of grasslands and woodlands, and other soil and crop management and land use practices that lead to carbon sequestration.

Over the past decade the sediments of many rivers, lakes, and estuaries have been contaminated by inorganic and organic materials. Contaminants from sediments, under certain conditions, can be released into overlying waters. Thus, sediments may be an important source of contaminants to waters in which littoral and atmospheric contaminants have been reduced or eliminated. Often found in aquatic sediments, metals are exposed to many reactions, such as sorption and precipitation, and are greatly influenced by the redox conditions in the sediment. The reactions - usually over a period of time - reflect biotic processing as well as chemical transformations. This book describes these important processes. Metal Contaminated Aquatic Sediments outlines advances in environmental chemistry, effective new modeling techniques, applications for biological treatment, and cycling and transport of trace metals in sedimentary environments. Each chapter contains a detailed reference section that draws upon a stunning array of sources. The book includes many figures and tables that illustrate the process under discussion. Features

This volume covers such areas in the field of soil salinity and water quality as: origin and distribution of salt-affected soils; management of alkali soils; quality criteria of irrigation water; wastewaters as a source of irrigation; and grasses and trees in the management of salt-affected soils.

Pesticide Interactions in Crop Production: Beneficial and Deleterious Effects evaluates the effects of pesticides on plants by exploring the physical, chemical, biological, and ecological interactions of pesticides that influence a crop. The effects of pesticides on the environment and on the crop pests themselves are considered as well. Specific topics addressed include iatrogenic responses, the fate of pesticides applied to cereals under field conditions, the persistance of pesticides on target crops, the effect of pesticides on soil symbionts, and the role of ecological agriculture on conventional and organic cropping systems. Pesticide Interactions in Crop Production: Beneficial and Deleterious Effects will be an important volume for agriculturalists, phytologists, mycologists, soil biologists, plant pathologists, tropical ecologists, arboriculturalists, and other researchers interested in the effects of pesticides on crops and soil.

Soil Management and Greenhouse Effect focuses on proper management of soils and its effects on global change, specifically, the greenhouse effect. It contains up-to-date information on a broad range of important soil management topics, emphasizing the critical role of soil for carbon storage. Sequestration and emission of carbon and other gases are examined in various ecosystems, in both natural and managed environments, to provide a comprehensive overview. This useful reference includes chapters that address policy issues, as well as research and development priorities. The material in this volume is valuable not only to soil scientists but to the entire environmental science community.

The sections in this handbook series reflect the input of different editors and advisory boards, and as a consequence, there is considerable variation in both the depth and coverage offered within a given area. However, an attempt has been made throughout to bring together pertinent information that will serve the needs of nonspecialists, provide a quick reference to material that might otherwise be difficult to locate, and furnish a starting point for further study.The project was undertaken with the realization that the initial volumes in the series could have some obvious deficiencies that will necessitate subsequent revisions. In the meantime, it is felt that the primary objectives of the Sections Editors and their Advisory Boards has been met in this first Edition.

Australia and the United States face very similar challenges in dealing with drought. Both countries cover a range of biophysical conditions, both are federations that provide considerable responsibility to state governments for water and land management, and both face the challenges in balancing rural industry and urban development, especially in relation to the allocation of water. Yet there are critical differences in their approaches to drought science and policy. Drought, Risk Management, and Policy: Decision Making under Uncertainty explores the complex relationship between scientific research and decision making with respect to drought in Australia and the United States. Risk Management, not Crisis Management Drawing on the work of respected academic researchers and policy practitioners, the book discusses the issues associated with decision making under uncertainty and the perspectives, needs, and expectations of scientists, policy makers, and resource users. Starting from the position that drought is a risk to be managed, it considers the implications of the predicted impacts of future climate change. The book also examines the policy responses to these challenges and the role of scientific input into the policy process. Contributors look at drought risk management in action and how end users in the community incorporate drought science into their decision making. The book concludes with lessons learned about science, policy, and managing uncertainty. Get Insight into the Relationship between Science and Policy-and How to Turn That into More Effective Decision Making Throughout, the contributors identify possible reasons for differences in the use and application of drought sciences and approach to policy between the two countries, offering valuable insight into the relationship between scientific advice and the policy process. They also highlight the challenges faced at the science-policy interface. Crossing international borders and disciplinary boundaries, this timely collection tackles drought policy development as part of the broader discussion about climate change. Although the focus is on Australia and the United States, many of the lessons learned are relevant for any country dealing with drought.

Offers a perspective on soils as earth materials, which establishes a pedological hierarchy of materials, processes and factors, and their rationalization in terms of plate tectonics. The book should interest soil and earth scientists.

Salt and Sediment Dynamics presents a thorough treatment of salt and sediment interactions and the implications of such interactions for sub-salt exploration. The book emphasizes and utilizes recent discoveries on many aspects of salt and sediment interactions, provides the theoretical framework for interpreting the increasing amount of available data on salt and sediments, and develops a self-consistent dynamical evolution model of salt structures and their interaction with surrounding sediments.
The model developed in the text consists of an evolving salt structure that influences sediment motion with self-consistent evolution of sediments and salt shape. The resulting stress and strain in the sediments and the thermal focusing effects of the salt are evaluated. The salt and sediments in the model are consistent with observed geometries, a result of having freely adjustable, observation-controlled model parameters.
In addition, the book describes case histories in a variety of geological settings, thus explaining aspects of the genesis and development of salt structures, of their impact on sedimentary structural evolution, and of the impact of sediments on salt masses.
The techniques developed by the authors expand the current state of knowledge regarding the evolution and dynamics of salt structures and increase the potential for effective sub-salt hydrocarbon exploration.

Loess is a product of aeolian deposition during the Quaternary glaciation cycles and covers approximately 6% of the Earth's land. The Loess Plateau of China, which is home to a population of nearly three hundred million, has the thickest and most complete loess strata, where loess geohazards occur most frequently due to the weak geoenvironment and dense human activities. In recent years, the engineering geological characteristics of loess and geohazards in loess areas have gradually received increasing attention from academic researchers. This book reviews an informative collection of up-to-date literature in this field. It presents the unique features of loess and loess geohazards, and provides a strong foundation for future study via eight systematically structured chapters, e.g., origin and spatial distribution, loess landforms, microstructure, physical properties, permeability, shear strength, tensile strength, and loess geohazard. It can serve as a principal reference for researchers, practical engineers and technicians who are engaged in loess geology and surface processes, and is suitable especially for undergraduate and postgraduate students in the field of loess engineering geology.

Despite the apparently desperate situation of sub-Saharan Africa, rainwater harvesting and management is a viable intervention for upgrading rain-fed agriculture, improving water supply and sustainable livelihoods in water-scarce river basins. If strategies are developed to ensure equity allocation of basin water, a win-win situation for diverse water users can be achieved. This thesis assesses the hydrological impacts of land use changes on water resources management and socio-economic development of the upper Ewaso Ng iro river basin in Kenya. It considers the impact of irrigation on dry season river flows and highlights the challenge of flood storage strategies. While flood storage can reduce dry season irrigation water abstractions by more than a half, without affecting hydro-ecological functions downstream, unplanned flood harvesting may impact negatively on flood flow, being detrimental to natural ecosystems and groundwater downstream.

In recent years, rapid technological advances and changes in agricultural management have taken place. These have yielded benefits to society but have also generated new and significant environmental problems. Novel questions and challenges relating to agricultural practice and soil microbial ecology, ecotoxicology, biotechnology, and bioremediation must be addressed. As a consequence, the fields of soil microbiology and biochemistry have been highlighted.
This book provides a modern, authoritative, and comprehensive collection of methods for the study of soil microbiology and biochemistry. Classical and modern, aerobic and anerobic, laboratory and field-based methods are presented. Detailed techniques are given, but in addition the theoretical basis behind such methodology is described, so that the origins and principles of the techniques are clear to the reader. Particular emphasis has been placed on uniform, simple, and clear presentation of the different methods.
With respect to bioremediation of soils, this work provides a unique bridge between general and applied soil microbiology and biochemistry, presenting an integrated discussion of concepts, theories, and methods. This book will be essential for all scientists and students actively involved in natural and environmental sciences and engineering, and for those working in industry, authorities, and consulting companies.
*
* Uniform and clear presentation of the different methods.
* Bridges the gap between general and applied soil microbiology.
* Maintains a balanced discussion of concepts, theories, and methods.
* Essential reading for all scientists and students involved in natural and environmental sciences and anyone working in the industry.

"This thought-provoking book demonstrates how processes of landscape transformation, usually illustrated only in simplified or idealized form, play out over time in real, complex landscapes. Trimble illustrates how a simple landscape disturbance, generated in this case by agriculture, can spread an astonishing variety of altered hydrologic and sedimentation processes throughout a drainage basin. The changes have spatial and temporal patterns forced on them by the distinctive topographic structure of drainage basins. "Through painstaking field surveys, comparative photographic records, careful dating, a skillful eye for subtle landscape features, and a geographer's interdisciplinary understanding of landscape processes, the author leads the reader through the arc of an instructive and encouraging story. Farmers-whose unfamiliarity with new environmental conditions led initially to landscape destruction, impoverishment, and instability-eventually adapted their land use and settlement practices and, supported by government institutions, recovered and enriched the same working landscape. "For the natural scientist, Historical Agriculture and Soil Erosion in the Upper Mississippi Valley Hill Country illustrates how an initially simple alteration of land cover can set off a train of unanticipated changes to runoff, erosion, and sedimentation processes that spread through a landscape over decades-impoverishing downstream landscapes and communities. Distinct zones of the landscape respond differently and in sequence. The effects take a surprisingly long time to spread through a landscape because sediment moves short distances during storms and can persist for decades or centuries in relatively stable forms where it resists further movement because of consolidation, plant reinforcement, and low gradients. "For the social scientist, the book raises questions of whether and how people can be alerted early to their potential for environmental disturbance, but also for learning and adopting restorative practices. Trimble's commitment to all aspects of this problem should energize both groups." -Professor Thomas Dunne, Bren School of Environmental Science and Management, UC Santa Barbara

Offers a perspective on soils as earth materials, which establishes a pedological hierarchy of materials, processes and factors, and their rationalization in terms of plate tectonics. The book should interest soil and earth scientists.