Advances in Soil Science: Volume 2

ISBN-13: 9781461295587 / Angielski / Miękka / 2011 / 235 str.

E. Bragg; J. M. Lynch; K. Mengel

Opis

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 is now being steadily degraded. The diversity of soil makes it cropland necessary for research to be conducted in many locations. There are basic principles, however, that are universal. This, Advances in Soil Sciences, presents 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. But most importantly, the contributors will develop principles that have practical applications to both developing and developed agricultures.

Spis treści

Developments in Soil Erosion and Deposition Models.- I. Introduction.- II. Hydrologic Models.- III. Controlled Research on Soil Erosion and Deposition Processes.- IV. Conceptualization of Erosion/Deposition Processes.- V. Erosion/Deposition Model of Rose et al..- VI. Application of Model of Rose et al..- VII. Comparison of the Modeling Approach of Foster et al. and Rose et al. for Overland Flow.- VIII. Sediment Deposition and Load-Bed Relationships.- IX. Simplified Theory of Rose et al. with Applications.- X. Some Brief Implications for Field Conservation Research and Conservation Planning.- Acknowledgments.- References.- Dynamics and Availability of Major Nutrients in Soils.- I. Introduction.- II. Factors and Processes of Plant Nutrient Availability.- III. Nitrogen.- IV. Phosphorus.- V. Potassium.- VI. Concluding Remarks.- References.- Microorganisms and Soil Aggregate Stability.- I. Introduction.- II. Why Is Stable Aggregation Necessary?.- III. How Are Microorganisms Involved?.- IV. What Are the Mechanisms Involved?.- V. Applications.- VI. Conclusions.- References.- The Distinctive Properties of Andosols.- I. Introduction.- II. Formation of Andosols.- III. Humus and Its Accumulation.- IV. Clay Minerals Particular to Andosols.- V. Formation and Transformation of Clay Minerals.- VI. Electric Charge Characteristics of Andosols.- VII. Cation Exchange in Andosols.- VIII. Reaction with Phosphates.- IX. Physical and Mechanical Properties.- X. Conclusions.- References.