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.

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.

First published in 1985. This book examines wide variety of ways in which environmental deterioration, in particular soil erosion, can be viewed and the implicit political judgements that often inform them. Using the context of developing countries, where the effects tend to be more acute due to underdevelopment and climatic factors, this work aims to examine this source of uncertainty and make explicit the underlying assumptions in the debate about soil erosion. It also rejects the notion that soil erosion is a politically neutral issue and argues that conservation requires fundamental social change. This title will be of interest to students of environmental and developmental studies.

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

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 handbook series includes several naturally occurring chemicals that exhibit biological activity. These chemicals are derived from plants, insects, and several microorganisms. Volume I of this series is covers the theory and practice of the strategies for pest control and methods for detection.Moreover, it presents extensive tables that provide the information you need to select the most appropriate bioassay for a particular plant growth regulator or hormone. In addition to the chapters on bioassays, Volume I provides a solid introduction to the theory and practice of natural pesticide use, including in-depth discussions of integrated management systems for weed and pest control, the state-of-the-art use of computers in pest management, and allelochemicals as natural protection. Guidelines on toxicological testing and EPA regulation of natural pesticides are also detailed.

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.

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.

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.

Providing an introduction, the scientific background, case studies and future perspectives of in-situ arsenic remediation technologies for soils, soil water and groundwater at geogenic and anthropogenic contaminated sites. The case studies present in-situ technologies about natural arsenic, specifically arsenate and arsenite, but also about organic arsenic compounds. This work covers geochemical, microbiological and plant ecological solutions for arsenic remediation. It will serve as a standard textbook for (post-)graduate students and researchers in the field of Environmental Sciences and Hydrogeochemistry as well as researchers, engineers, environmental scientists and chemists, toxicologists, medical scientists and even for general public seeking an in-depth view of arsenic which had been classed as a carcinogen. This book aims to stimulate awareness among administrators, policy makers and company executives of in-situ remediation technologies at sites contamined by arsenic and to improve the international cooperation on the subject.

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.

Conservation tillage systems have been adopted by farmers in many countries to solve the problem of land degradation and declining water productivity. Direct application of such tillage systems has not been possible among resource-poor, smallholder farmers in semi-arid areas of Ethiopia. Problems such as the lack of rainfall, the costs of herbicides and implements, and the special cultivation needs of the crop tef, which can not be planted in rows, have developed locally-adapted conservation tillage systems. This book considers traditional tillage systems and the results of tests carried out on appropriate conservation tillage implements and systems for smallholder farmers in semi-arid regions of Ethiopia. The traditional tillage implement, the Maresha Plough, and the related tillage systems were identified as being the main cause of repeated and cross-ploughing, leading to land degradation and reduced water productivity. Modified implements were found to be suitable for conservation tillage systems while being simple, light and affordable. Two types of tillage systems developed for maize and tef were found to reduce surface runoff, increase availability of water to crops and increase yields.

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.

The present book highlights importance of mycorrhiza in soil genesis wherein it reflects mycorrhizal occurrence and diversity, various tools to characterize them and its impact on soil formation/health together with crop productivity. The edited compendium provides glimpses on the mycorrhizal fungi and their prominent role in nutrient transfer into host plants, and presenting view on application of mycorrhiza for crop biofortification. It focuses on the mechanisms involve in weathering process employed by mycorrhiza with highlighting the current and advanced molecular approaches for studying mycorrhizal diversity. Further, book emphasizes following aspects in details: significance of AMF in phytoremediation of hydrocarbon contaminated sites, the role of mycorrhiza in soil genesis using scientometric approach, the concept of mycorrhizosphere, xenobiotic metabolism, molecular approaches for detoxifying the organic xenobiotics and the role of mycorrhizosphere in stabilizing the environment in an eco-friendly way. In addition, the book will be benign to researchers that involved in mycorrhiza characterization especially by deploying metagenomics/PCR based and non PCR based molecular techniques that may be utilized to study the microbial diversity and structure within the mycorrhizosphere.

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.

The development of centrifuge technology presents geotechnical engineers with a very powerful and sophisticated technique for investigating geotechnical problems. The centrifuge can make significant contributions to understanding the mechanics of geotechnical materials and to the development of new analytical methods, and is widely accepted as an excellent technique for modelling specific situations. With the range of machinery and ancillary equomnt avaiwe and the increasing expertise of the engineering community, the centrifuge test has become a very important tool for sowing many geotechnical engineering problems. In this book, a team of practitioners provides a comprehensive overview of centrifuge testing. Starting from first principles and practical considerations, the book then discusses applications of the test in modelling such geotechnical structures and processes as foundations and retaining walls, environmental geomechanics and cold regions engineering. Professional and academic geotechnical, civil and structural engineers should find this a compact and thorough discussion of centrifuge testing.

Pathogen removal mechanisms in macrophyte and algal-based waste stabilization ponds were studied in Ghana and Colombia. The macrophytes used were water lettuce (Pistia stratiotes) and duckweeds (Lemna paucicostata and Spirodela polyrhiza). The selection of the species was based on economic importance and availability. Lemna was used during the initial investigations. However, Lemna could not withstand the ammonia levels in the wastewater used. Spirodela polyrhiza a rarer species in Ghana was therefore used in subsequent studies. The main mechanisms considered in this study were pH, protozoa predation and surface attachment. The microorganisms used were faecal bacteria namely; Escherichia coli, other coliforms, Salmonella sp., other enterobacteria, E. coli, ATCC13706 and enterococci. Studies were conducted using batch scale, continuous flow bench and pilot scale ponds. Results indicated in order of importance that long retention periods, attachment, sedimentation, predation and low pH are mechanisms in macrophyte ponds enhancing faecal bacteria removal, while in the algal ponds long retention periods, sunlight penetration, high pH, attachment and sedimentation are the mechanisms of importance in faecal bacteria removal. Presence of protozoa was also found to be important but true grazing studies could not be quantified. Dissolved oxygen did not play a major role in faecal bacteria removal.

Signi?cant technological advances have been few and far between in the past approximately one hundred years of soil survey activities. Perhaps one of the most innovative techniques in the history of soil survey was the introduction of aerial photographs as base maps for ?eld mapping, which replaced the conventional base map laboriously prepared by planetable and alidade. Such a relatively simple idea by today's standards revolutionized soil surveys by vastly increasing the accuracy and ef?ciently. Yet, even this innovative approach did not gain universal acceptance immediately and was hampered by a lack of aerial coverage of the world, funds to cover the costs, and in some cases a reluctance by some soil mappers and cartog- phers to change. Digital Soil Mapping (DSM), which is already being used and tested by groups of dedicated and innovative pedologists, is perhaps the next great advancement in delivering soil survey information. However, like many new technologies, it too has yet to gain universal acceptance and is hampered by ignorance on the part of some pedologists and other scientists. DSM is a spatial soil information system created by numerical models that - count for the spatial and temporal variations of soil properties based on soil - formation and related environmental variables (Lagacheric and McBratney, 2007).

This work contains results of the latest studies on the composition, structure and properties of humic substances, which are the largest and most important component of organic matter of different types of soils. It should be useful for soil scientists and nature conservationists.

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.

There are approximately 500 different soil varieties in Malaysia, most is residual soil and coastal alluvial soil. This book presents a comprehensive overview of various aspects of soils in Malaysia. It covers topics including climate; flora and fauna; geology and hydrology; land use changes for agriculture; soil fertility; human-induced soil degradation; and soil contamination sources. It features information on the role of biological, chemical, mechanical, and physical factors in relation to soil properties. The book highlights land use impact, soil problems arising from contamination and its control methods, the management of problem soils, limiting materials as well as future soil issues. The presentation of different soils in Malaysia is organized through chapters based on two major soil groups (a) the sedentary soils formed in the interior on a wide range of rock types, and (b) the soils of the coastal alluvial plains. The book features information on how these various soil types affect the economy of the country and highlights the soil issues and challenges within the context of sustainable agriculture. Useful to graduate students of soil science, professionals, and agriculturalists, it provides extensive knowledge of agriculture soils in Malaysia in a concise and user-friendly manner.

Emphasizing pioneering achievements, this work offers a clear and systematic description of various soil-water phenomena and their applications to soil problems such as water retention and the flux of water in soils and clays. This second edition contains material on the physical properties of adsorbed water, the application of fractal theory to solute and water flows in field soils, fingering research, and more.