Advances in Soil Science

Reactions Controlling Heavy Metal Solubility in Soils.- I. Introduction.- II. Ion-Exchange on Layer Silicates.- III. Chemisorption on Mineral Surfaces.- IV. Nucleation, Precipitation, and Solid Solutions.- V. Redox Processes Affecting Metal Solubility.- VI. Metal Adsorption by Organic Matter.- VII. Speciation of Metals in Solution.- VIII. Summary.- References.- The Components of Nitrogen Availability Assessments in Forest Soils.- I. Introduction.- II. The Framework.- III. The Methods.- IV. Conclusions.- Acknowledgments.- References.- Carbon Sources for Bacterial Denitrification.- I. Introduction.- II. Carbon Sources.- III. Natural C Substrates.- IV. Coculture and Multiculture Systems.- V. Decomposition of Organic Materials and Denitrification.- VI. Denitrification in Relation to Measured Available Soil C Substrate.- VII. Denitrification Near Roots.- VIII. Acetylene as a C Substrate for Denitrifiers.- IX. Denitrification Kinetics Involving C Substrates.- X. Denitrification Versus Dissimilatory Nitrate Reduction.- XI. Summary.- Acknowledgments.- References.- Integrated Nitrogen Management in Irrigated Rice.- I. Introduction.- II. Efficiency of Nitrogen Fertilizer.- III. Ammonia Volatilization Loss.- IV. Denitrification Loss.- V. Management Agenda to Increase Nitrogen Use Efficiency.- VI. Supplemental Sources of Nitrogen.- VII. Knowledge Gaps.- References.- Tropical Soils and Soil Classification Updates.- I. Introduction.- II. Keys to Soil Taxonomy 1987.- III. The FAO-UNESCO 1988 Update.- IV. Classifications and Soils of the Tropics.- References.