Xem 1-20 trên 1512 kết quả Soil
  • The stability and performance of a structure founded on soil depend on the subsoil conditions, ground surface features, type of construction, and sometimes the meteorological changes. Subsoil conditions can be explored by drilling and sampling, seismic surveying, excavation of test pits, and by the study of existing data. Elaborate site investigation oftentimes cannot be conducted due to a limited assigned budget. For very favorable sites, such investigation may not be warranted.

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  • During the past two centuries, scientists, farmers, and agricultural educators have tended to alternate their views of soil organic matter (SOM) between the extremes of great appreciation and low esteem. As an early 20th century bulletin explained, organic matter was “once extolled as the essential soil ingredient, the bright particular star in the firmament of the plant grower…” before it “…fell like Lucifer…” as a result of the findings of 19th century agricultural chemists that most of the plant structure (C, that is) originated in the atmosphere (Hills et al., 1908)....

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  • This volume is an update of the book, Soil Sampling and Methods of Analysis, first published in 1993. The aims of this second edition remain the same as those of the earlier edition—to provide a compilation of soil analytical and sampling methods that are commonly used, straightforward, and relatively easy to use. The materials and procedures for these methods are presented with sufficient detail and information, along with key references, to characterize the potential and limitation of each method....

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  • Why do some contaminants remain in soils indefinitely? How much of a threat do they pose to human health or the environment? The need for effective and economic site decontamination arises daily. Geoenvironmental Engineering: Contaminated Soils, Pollutant Fate, and Mitigation discusses why soils remain contaminated, focusing on the development of the factors, properties, characteristics, and parameters of soils and individual contaminants.

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  • Soil mechanics involves a combination of engineering mechanics and the properties of soils. This description is broad and can encompass a wide range of soil types. These soils could either be saturated with water or have other fluids in the voids (e.g., air). The development of classical soil mechanics has led to an emphasis on particular types of soils. The common soil types are saturated sands, silts and clays, and dry sands. These materials have been the emphasis in soil mechanics textbooks.

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  • Characterizing the nature of heavy metal release reactions, sorption mechanisms, and movement in the soil is the main topic of this book. Because soils are heterogeneous, heavy metals in soils can be involved in a series of complex chemical and biological interactions including oxidation-reduction, precipitation and dissolution, volatilization, and surface and solution phase complexation. The heterogeneous nature of the different soil constituents adds to the complexity of interactions of heavy metal species with the soil environment....

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  • For much of history, few things have mattered more to humans than their relations with soil. This is evidenced by a rich historical literature on aspects of soil management and soil fertility, dating back to texts of ancient civilizations of the Middle East, the Mediterranean, China, and India (see McNeill and Winiwarter 2004).

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  • The Encyclopedia of Soils in the Environment is a vitally important scientific publication and an equally important contribution to global public policy. The Encyclopedia brings together a remarkable range of cutting-edge scientific knowledge on all aspects of soil science, as well as the links of soils and soil science to environmental management, food production, biodiversity, climate change, and many other areas of significant concern.

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  • Dr Samuel Johnson is reputed to have said ‘what is written without effort is in general read without pleasure’. This edition of Principles and Practice of Soil Science has certainly taken much effort to complete, so I hope it will be enjoyed and provide valuable information to as wide an audience of interested readers as possible.

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  • Soil fertility describes soil nutrient status and the factors controlling the supply of nutrients to plants. Continued efforts to improve soil fertility are required to support the world's growing demand for food, fiber, and renewable fuels. Important ecological services provided by soils, such as biodiversity, buffering capacity, and nutrient recycling benefit from the amendments applied to sustain soil fertility. Those amendments need to be applied in a manner that is both economical and practical for the producer to achieve agronomic objectives that are environmentally sound.

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  • “Essentially, all life depends upon the soil. There can be no life without soil and no soil without life; they have evolved together.” - Charles E. Kellogg, USDA Yearbook of Agricul‐ ture, 1938. Natural processes and human activities alter the properties and quality of soils over time. The assessment of soil quality entails the evaluation of the capability of a soil to perform its functions not only in present scenarios but also how those functions can be preserved for future land...

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  • Soils are aggregates of mineral particles, and together with air and/or water in the void spaces, they form three-phase systems. A large portion of the earth’s surface is covered by soils, and they are widely used as construction and foundation materials. Soil mechanics is the branch of engineering that deals with the engineering properties of soils and their behavior under stress.

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  • Microbial biomass formation on root surfaces can be measured in plants growing in solution with or without an inert solid support. Carbon flow to the biomass can be measured by growing plants in solution or soil on a continuous source of 14C02 and the expected biomass formation predicted. The lack of correlation between measured and predicted biomass can be explained by oligotrophic growth of the micro-organisms.

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  • The book deals with several aspects of soil erosion, focusing on its connection with the agricultural world. Chapters' topics are various, ranging from irrigation practices to soil nutrient, land use changes or tillage methodologies. The book is subdivided into fourteen chapters, sorted in four sections, grouping different facets of the topic: introductive case studies, erosion management in vineyards, soil erosion issue in dry environments, and erosion control practices.

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  • This book is a response to that need for a synthesis. It contains 17 chapters, each prepared by authors who are internation- ally recognized for their knowledge and expertise in a particular area of soil/plant biology.

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  • Soil erosion affects a large part of the Earth surface, and it represents one of the most relevant environmental problems worldwide. Intense land degradation processes that destroyed civilizations in the past are still going on at present. Accelerated soil erosion is one of the main soil threats, as the natural balance between soil formation and loss may be seriously compromised, leading to desertification and permanent loss of fertility and protective function. Soil erosion is not only related to agricultural activities and farming practices, but also to land management in general....

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  • Suggested citation for this report: Anne Turbé, Arianna De Toni, Patricia Benito, Patrick Lavelle, Perrine Lavelle, Nuria Ruiz, Wim H. Van der Putten, Eric Labouze, and Shailendra Mudgal. Soil biodiversity: functions, threats and tools for policy makers. Bio Intelligence Service, IRD, and NIOO, Report for European Commission (DG Environment), 2010.

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  • “Be it deep or shallow, red or black, sand or clay, the soil is the link between the rock core of the earth and the living things on its surface. It is the foothold for the plants we grow. Therein lays the main reason for our interest in soils.” --- Roy W. Simonson, USDA Yearbook of Agriculture, 1957. The British naturalist Charles Darwin (1809–1882) was probably the first scientist to examine a soil profile and suggest factors responsible for the structure of the various layers.

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  • Soil provides a list of services to all users of terrestrial ecosystems and is crucial to our agricultural societies. From an anthropogenic point of view, soil quality may be then measured in terms of the services the soil provides to our society. The value of soil services to human societies has changed during history and thus the value we give to soils has also changed over time as it depends upon the economic and cultural basis of a society for a given context. While throughout history human awareness of the soil services has been mainly reduced to food, fibre and...

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  • Soil contamination has severely increased over the last decades, mainly due to petroleum hydrocarbons, solvents, pesticides, lead and other heavy metals from industrial wastes and human activities. The critical point regarding contaminated soil monitoring is the intrinsic difficulty in defining fixed monitoring variables and indicators as the establishment of any a priori criterion and threshold for soil quality can be still considered subjective.

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