Set includes revised editions of some issues.

Examining the role of engineering in delivery of quality consumer products, this expansive resource covers the development and design of procedures, equipment, and systems utilized in the production and conversion of raw materials into food and nonfood consumer goods. With nearly 2000 photographs, figures, tables, and equations including 128 color figures the book emphasizes and illustrates the various engineering processes associated with the production of materials with agricultural origin. With contributions from more than 350 experts and featuring more than 200 entries and 3600 references, this is the largest and most comprehensive guide on raw production technology.

The purpose of Advances in Soil Science is to provide a forum for leading scientists to analyze and summarize the available scientific information on a subject, assessing its importance and identifying additional research needs. A wide array of subjects has been addressed by authors from many countries in the initial ten volumes of the series. The quick acceptance of the series by both authors and readers has been very gratifying and confirms our perception that a need did exist for a medium to fill the gap between the scientific journals and the comprehensive reference books. This volume is the first of the series devoted entirely to a single topic soil degradation. Future volumes will include both single-topic volumes as well as volumes containing reviews of different topics of soil science, as in the case of the first ten volumes. There are increasing concern and attention about managing natural re sources, particularly soil and water. Soil degradation is clearly one of the most pressing problems facing mankind. Although the spotlight regarding soil degradation in recent years has focused on Africa, concern about the degradation of soil and water resources is worldwide. The widespread con cern about global environmental change is also being linked to severe problems of soil degradation. Therefore, we are indeed pleased that the first volume of the series devoted to a single topic addresses such an impor tant issue. The current volume is also the first of the series involving a guest editor.

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.