S. Henin Versailles, France It was a pleasure for me to take part in the NATO Advanced Study Workshop for studies of 'Soil Colloids and their Associations in Soil Aggregates'. The meeting provided me with a welcome opportunity to renew acquaintances with respected colleagues in the various fields of Soil Science, to listen to their presentations, and be involved in discussions which were at the frontiers of the science which deals with the structures and the associations of the soil colloidal constituents. In my view the rapid advances in Soil Science, and the great benefits to agriculture from these, have their origins in the emerging understanding of the structures and the associations of the different soil colloids. It is clear that much research is still needed before the molecular details of the most important of the structures and of the interactions are fully understood. The associations between the soil colloids, and the manner in which they bind to or hold the other constituents of soils in aggregates is fundamental to soil fertility. and the Modem intensive agriculture leads to the degradation of soil structure subsequent loss through erosion of a resource that is vital for the production of food. This degradation is considered to result primarily from the biological oxidation of the indigenous soil organic matter, and from the failure to return to the soil sufficient organic residues to compensate for such losses.

S. Henin Versailles, France It was a pleasure for me to take part in the NATO Advanced Study Workshop for studies of 'Soil Colloids and their Associations in Soil Aggregates'. The meeting provided me with a welcome opportunity to renew acquaintances with respected colleagues in the various fields of Soil Science, to listen to their presentations, and be involved in discussions which were at the frontiers of the science which deals with the structures and the associations of the soil colloidal constituents. In my view the rapid advances in Soil Science, and the great benefits to agriculture from these, have their origins in the emerging understanding of the structures and the associations of the different soil colloids. It is clear that much research is still needed before the molecular details of the most important of the structures and of the interactions are fully understood. The associations between the soil colloids, and the manner in which they bind to or hold the other constituents of soils in aggregates is fundamental to soil fertility. and the Modem intensive agriculture leads to the degradation of soil structure subsequent loss through erosion of a resource that is vital for the production of food. This degradation is considered to result primarily from the biological oxidation of the indigenous soil organic matter, and from the failure to return to the soil sufficient organic residues to compensate for such losses.

About 20 years ago the emphasis in soil chemistry research switched from studies of problems related to scarcities of plant nutrients to those arising from soil pollutants. The new problems have come about because of the excessive uses of fertilizers, the inputs from farm and industrial wastes, the widespread applications of anthropogenie xenobiotic chemicals, and the deterioration of soil structure resulting from certain modern agriculture practises. The International Society of Soil Science (ISSS) recognized these problems and challenges. A provisional Working Group was set up in 1978 to focus attention on soil colloids with a view to understanding better the interactions wh ich take place at their surfaces. It was recognized that these interactions are fundamental to problems of soil fertility, as weIl as to those of soil pollution. After the group had received the official support of ISSS at its 12th International Congress in New Delhi in 1982 it set as its priority the assembling and evaluation of information, relevant to the soil and environmental sciences, concerning the composition and structure of soil colloids. Prior to that aseries of Position Papers were published in the Bulletin of the International Society of Soil Science (Vol. 61, 1981) outlining the state of knowledge about the composition and properties of soil colloids.

Principles of Soil Physics examines the impact of the physical, mechanical, and hydrological properties and processes of soil on agricultural production, the environment, and sustainable use of natural resources. The text incorporates valuable assessment methods, graphs, problem sets, and tables from recent studies performed around the globe and offers an abundance of tables, photographs, and easy-to-follow equations in every chapter. The book discusses the consequences of soil degradation, such as erosion, inhibited root development, and poor aeration. It begins by defining soil physics, soil mechanics, textural properties, and packing arrangements . The text continues to discuss the theoretical and practical aspects of soil structure and explain the significance and measurement of bulk density, porosity, and compaction. The authors proceed to clarify soil hydrology topics including hydrologic cycle, water movement, infiltration, modeling, soil evaporation, and solute transport processes. They address the impact of soil temperature on crop growth, soil aeration, and the processes that lead to the emission of greenhouse gases. The final chapters examine the physical properties of gravelly soils and water movement in frozen, saline, and water-repellant soils. Reader-friendly and up-to-date, Principles of Soil Physics provides unparalleled coverage of issues related to soil physics, structure, hydrology, aeration, temperature, and analysis and presents practical techniques for maintaining soil quality to ultimately preserve its sustainability.

By 2050, the demand for water to sustain world agriculture will increase by seventy-five per cent in order to feed an estimated nine billion inhabitants. Increased amounts of water will be required for irrigation and for industrial and domestic use. Natural ecosystems will be threatened by the expansion of agricultural land and by a reduction in water availability, while climate change will exacerbate the situation. Management of available resources, particularly groundwater, will become more critical and aquifers will need to be managed for the benefit of all. These selected papers were first presented at the International Association of Hydrogeologists, Dijon 2006, and are divided into six themes: large aquifers, resource assessment; large aquifers, water salinity and evolution; karstic and carbonate aquifer systems; geothermal aquifer systems; aquifer contamination studies and aquifer monitoring systems and management. The volume also includes a short biography of Henry Darcy and illustrates his contribution to science. Five invited contributions describe modern methods for estimating the hydraulic conductivity of aquifers.

Wechselwirkungen von Mineralien, organischen Verbindungen und Mikroorganismen im Boden: Dieses Handbuch wertet aktuelle Forschungsergebnisse auf diesem Gebiet kritisch aus und erläutert die Bedeutung der Zusammenhänge für Ökosysteme. Ein besonderer Schwerpunkt bildet die Wechselbeziehung zwischen Schadstoffen im Boden und Populationen von Mikroorganismen.

Soils comprise the largest pool of terrestrial carbon and therefore are an important component of carbon storage in the biosphere-atmosphere system. Structure and Organic Matter Storage in Agricultural Soils explores the mechanisms and processes involved in the storage and sequestration of carbon in soils. Focusing on agricultural soils - from tropical to semi-arid types - this new book provides an in-depth look at structure, aggregation, and organic matter retention in world soils. The first two sections of the book introduce readers to the basic issues and scientific concepts, including soil structure, underlying mechanisms and processes, and the importance of agroecosystems as carbon regulators. The third section provides detailed discussions of soil aggregation and organic matter storage under various climates, soil types, and soil management practices. The fourth section addresses current strategies for enhancing organic matter storage in soil, modelling techniques, and measurement methods. Throughout the book, the importance of the soil structure-organic matter storage relationship is emphasized. Anyone involved in soil science, agriculture, agronomy, plant science, or greenhouse gas and global change studies should understand this relationship. Structure and Organic Matter Storage in Agricultural Soils provides an ideal source of information not only on the soil structure-storage relationship itself, but also on key research efforts and direct applications related to the storage of organic matter in agricultural soils.