Advances in Soil Science: 1

The world population in 1930 was 2 billion. It reached 3 billion in 1960, stands at 4. 6 billion today, and is expected to reach 6 billion by the end of the century. The food and fiber needs of such a rapidly increasing population are enormous. One of the most basic resources, perhaps the most basic of all, for meeting these needs is the soil. There is an urgent need to improve and protect this resource on which the future of mankind directly depends. We must not only learn how to use the soil to furnish our immediate needs, but also ensure that the ability of the soil to sustain food production in the future is unimpaired. This is indeed a mammoth task; a 1977 United Nations survey reported that almost one-fifth of the world's cropland is now being steadily degraded. This volume is the first of a new series entitled Advances in Soil Science. The diversity of soil makes it necessary for research to be conducted in many locations. There are basic principles, however, that are universal. This new series will present clear and concise reviews in all areas of soil science for everyone interested in this basic resource and man's influence on it. The purpose of the series 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.

Table of Contents:
Soil Management for Optimized Productivity Under Rainfed Conditions in the Semi-Arid Tropics.- I. Introduction.- II. Soils of the Semi-Arid Tropics.- III. Major Characteristics of SAT Vertisols and Alfisols.- IV. Dryland Management Options for SAT Vertisols and Alfisols.- V. Conclusions.- References.- Soil Profile Modification for Increasing Crop Production.- I. Introduction.- II. Literature Review and Discussion.- III. Summary.- References.- The Effect of Exchangeable Sodium and Electrolyte Concentration on Crust Formation.- I. Introduction.- II. Crust Properties as Determined by the Infiltration Rate (IR).- III. Effect of ESP and Electrolyte Concentration on the Structure of the Soil Crust.- IV. Effect of Soil Sodicity on Crust Formation (and Rain Infiltration)-Field Studies.- V. Summary.- References.- Ammonia Volatilization from Ammonium or Ammonium-Forming Nitrogen Fertilizers.- I. Introduction.- II. Methods for Estimating NH3 Volatilization.- III. Chemistry of NH3 Volatilization.- IV. Magnitude of NH3 Losses.- V. Chemical and Physical Parameters That Control Absolute NH3 Losses.- VI. Ammonia Loss from Flooded Systems.- VII. Volatilization Loss of Nitrogen Following Forest Fertilization.- VIII. Ammonia Transfer Cycle.- IX. Conclusion.- References.- The Effect of Pedogenic Environments on Iron Oxide Minerals.- I. Introduction.- II. Pedoenvironments and Fe(III) Oxide Minerals.- III. Aluminum Substitution.- IV. Pedoenvironments and Crystal Quality.- V. Iron Oxide Minerals and Soil Classification.- References.- Soil Testing.- I. Introduction.- II. Research Required as a Basis for Soil Testing.- III. Taking the Sample.- IV. Laboratory Procedures.- V. Soil Test Calibration and Interpretation.- VI. Rating Soil-Test Values and Use of a Fertility Inde.- VII. Making Lime and Fertilizer Recommendations from Soil Tests.- References.- Boron in Water, Soils, and Plants.- I. Introduction.- II. Boron Chemistry in Aqueous Media.- III. Boron-Soil Interaction.- IV. Boron in Soil-Plant Relations.- V. Soil Reclamation and Management.- References.- Relationship between Soil Physical Properties and Crop Production.- I. Introduction.- II. Factors Directly Affecting Plant Growth.- III. Factors Indirectly Affecting Plant Growth.- IV. Interrelationships of Soil Physical Factors.- V. Relationships between Soil Physical Conditions and Management.- VI. Soil Erosion and Productivity.- VII. Conclusions.- References.