Soil Compaction in Agriculture: A View Toward Managing the Problem. - I. Introduction. - II. The Machine-Soil-Crop System. - III. Establishing a Decision Framework. - IV. Summary and Conclusions. - Acknowledgments. - References. - Hardsetting Soils: Behavior Occurrence and Management. - I. Introduction. - II. Scientific Basis for Hardsetting Behavior. - III. Soil Classification and Occurrence of Hardsetting Soils. - IV. Management and Amelioration of Hardsetting Soils. - V. Research and Development Priorities. - Acknowledgments. - References. - Role of Plinthite and Related Forms in Soil Degradation. - I. Introduction. - II. Definition of Plinthite and Associated Forms. - III. Processes Leading to Accumulation of Sesquioxides. - IV. Occurrence and Distribution. - V. Management Implications. - VI. Conclusion. - References. - Soil Erosion and Land Degradation: The Global Risks. - I. Introduction. - II. Technical Data on Soil Erosion. - III. Soil Erosion by Water. - IV. Wind Erosion. - V. Soil Erosion in the Tropics versus Temperate Regions. - VI. Soil Erosion and Food Production in the Tropics. - VII. Soil Erosion in Different Geographic Regions. - VIII. Conclusions. - References. - Soil Wetness and Anaerobiosis. - I. Introduction. - II. Causes of Soil Wetness. - III. Effects of Soil Wetness. - IV. Reclaiming Wet Soils. - V. Conclusions. - References. - Chemical Degradation of Soil. - I. Introduction. - II. Chemical Processes in Soil. - III. Examples of Chemical Soil Degradation. - IV. Prevention and Restoration of Chemically Degraded Soils. - V. Conclusions. - References. - Salt-Affected Soils: Their Reclamation and Management for Crop Production. - I. Introduction. - II. Classification of Salt-Affected Soils. - III. Measuring Salinity Alkalinity and Sodicity; Some Interrelationships and Influences on Soil Properties. - IV. Reclaiming Alkali Soils. - V. Crop Management in Alkali Soils. - VI. Reclamation of Saline Soils. - VII. Conclusions. - VIII. Perspective. - Acknowledgments. - References. - Biological Degradation of Soil. - I. Introduction. - II. Microbial Communities in Soil. - III. Aspects of Soil Biology Affected by Land Degradation. - IV. Effects of Toxic Substances on Microorganisms. - V. Effects of Mining Operations on Soil Biology. - VI. Effects of Land Management Practices on Soil Biology. - VII. Microorganisms as Pollutants. - VIII. Conclusions. - References. - Need for Action: Research and Development Priorities. - I. Introduction. - II. Resource Inventory. - III. Separating Emotions from Facts. - IV. Restoring Productivity of Degraded Lands. - V. Reaching Out. - VI. Conclusions. - References. Language: English