Impact Of Water And External Forces On Soil Structure

Improving the bearing capacity of top soil by means of a polymer mixture grout. Soil erosion and soil structure. Simulation of gas diffusion. Stability of clay aggregates as a function of water regimes. Strength of soil aggregates and of aggregate beds. Compressibility of arable land. The reference base for compaction state of soils. An example of numerical modelling - expansion of a root cavity in soil. Mechanical consolidation in volcanic ash soils. Selected physical properties of three soil types as affected by land use. A method for characterizing the state of compactness of an arable soil. Soil compaction and water uptake of plants. Dynamic impact on soil structure due to traffic of Off-road vehicles. Changes in bulk density and pore water pressure during soil compression. A method to predict workability of arable soils and its influence on crop yield. Prediction of the compressibility of arable land. Effect of wheeling with heavy machinery on soil physical properties. Impact of external forces on soil structure.

This book is a specialized monograph on soil physical conditions and root-system relations. It attempts to explain the importance of physical properties of soil by showing how they affect root growth and functions; and on the other hand, how roots themselves change their environment. Emphasis is placed on the interactive effects of soil physical factors. An attempt has been made to analyze the possibilities of the root system‘s modification by both soil and plant management.The book is addressed to research workers and advanced students in soil and plant sciences and may also be of interest to agronomists and related specialists.

This book provides a global review of the mechanisms, incidence and control measures related to the problems of soil compaction in agriculture, forestry and other cropping systems. Among the disciplines which relate to this subject are soil physics, soil mechanics, vehicle mechanics, agricultural engineering, plant physiology, agronomy, pedology, climatology and economics. The volume will be of great value to soil scientists, agricultural engineers, and all those involved with irrigation, drainage and tillage. It will help to facilitate the exchange of information on current work throughout the world, as well as to promote scientific understanding and stimulate the development, evaluation and adoption of practical solutions to these widespread and urgent problems.

Agricultural soils are subjected to many applied mechanical stresses that influence their behavior. Stresses arise from tillage machines, seeders and chemicals applicators, tractors, and equipment for harvest and transport. Applied stresses may compact or loosen the bulk soil. Micro sections of soil (aggregates or clods) may be compacted during tillage while the bulk soil is loosened. Because most granular soils are combined into structural units of varying sizes with different strengths and properties, prediction of the effect of stresses on the behavior of bulk soils is difficult. The basic strength properties of soil are determined by many fac tors: the size distribution of particles, chemical and mineralogical properties of inorganic clay fraction, the organic matter content and composition, the water content and the stress history. These factors combine and interact to produce many possible behavior patterns. Changes in structure of the soil from applied stresses and biologi cal reactions may profoundly influence storage and transmission of water, heat, and air, and the mechanical resistance to penetration by plant roots. They may also affect the traction of vehicles. Manipulation of structural properties of soils by tillage implements is a major cost under most crop production systems. Reduced energy use is also a significant conservation objective. Improved management systems are very dependent upon a better understanding of soils' response to applied stresses. The content of this book resulted from a NATO Advanced Research Workshop held in St. Paul, Minnesota, U.S.A. September 13-16, 1988.

This Encyclopedia of Agrophysics will provide up-to-date information on the physical properties and processes affecting the quality of the environment and plant production. It will be a "first-up" volume which will nicely complement the recently published Encyclopedia of Soil Science, (November 2007) which was published in the same series. In a single authoritative volume a collection of about 250 informative articles and ca 400 glossary terms covering all aspects of agrophysics will be presented. The authors will be renowned specialists in various aspects in agrophysics from a wide variety of countries. Agrophysics is important both for research and practical use not only in agriculture, but also in areas like environmental science, land reclamation, food processing etc. Agrophysics is a relatively new interdisciplinary field closely related to Agrochemistry, Agrobiology, Agroclimatology and Agroecology. Nowadays it has been fully accepted as an agricultural and environmental discipline. As such this Encyclopedia volume will be an indispensable working tool for scientists and practitioners from different disciplines, like agriculture, soil science, geosciences, environmental science, geography, and engineering.

Sustainable agriculture embodies many concepts in its attempt to integrate all the aspects of farming systems into a holistic system. This book explores the processes that occur within the components of a sustainable system and shows where we can build upon our existing knowledge to develop the concepts of sustainable agriculture into the new conventional agriculture. Well-known researchers examine a variety of aspects, including production goals, environmental considerations, and economics, to build a knowledge base that allows readers to see where changes in agriculture must be made and how challenges can be met. They compare existing systems against definitions of sustainability and pinpoint those areas where improvements can be made in current systems to further the concepts of sustainability.